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| author | Mauro Carvalho Chehab <mchehab+huawei@kernel.org> | 2020-04-28 00:01:24 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2020-04-28 14:38:38 -0700 |
| commit | a362032eca22d03071c4613f6ca503be982bf375 (patch) | |
| tree | bf1464f9d96bacfa42cc0035b9d1f3a54efa53bc /Documentation | |
| parent | b5fcf32d7d4b647c0f3aa612d91d25996a49bcd9 (diff) | |
| download | lwn-a362032eca22d03071c4613f6ca503be982bf375.tar.gz lwn-a362032eca22d03071c4613f6ca503be982bf375.zip | |
docs: networking: convert bonding.txt to ReST
- add SPDX header;
- adjust titles and chapters, adding proper markups;
- comment out text-only TOC from html/pdf output;
- mark code blocks and literals as such;
- mark tables as such;
- add notes markups;
- adjust identation, whitespaces and blank lines;
- add to networking/index.rst.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/networking/bonding.rst (renamed from Documentation/networking/bonding.txt) | 1315 | ||||
| -rw-r--r-- | Documentation/networking/device_drivers/intel/e100.rst | 2 | ||||
| -rw-r--r-- | Documentation/networking/device_drivers/intel/ixgb.rst | 2 | ||||
| -rw-r--r-- | Documentation/networking/index.rst | 1 |
4 files changed, 687 insertions, 633 deletions
diff --git a/Documentation/networking/bonding.txt b/Documentation/networking/bonding.rst index e3abfbd32f71..dd49f95d28d3 100644 --- a/Documentation/networking/bonding.txt +++ b/Documentation/networking/bonding.rst @@ -1,10 +1,15 @@ +.. SPDX-License-Identifier: GPL-2.0 - Linux Ethernet Bonding Driver HOWTO +=================================== +Linux Ethernet Bonding Driver HOWTO +=================================== - Latest update: 27 April 2011 +Latest update: 27 April 2011 + +Initial release: Thomas Davis <tadavis at lbl.gov> + +Corrections, HA extensions: 2000/10/03-15: -Initial release : Thomas Davis <tadavis at lbl.gov> -Corrections, HA extensions : 2000/10/03-15 : - Willy Tarreau <willy at meta-x.org> - Constantine Gavrilov <const-g at xpert.com> - Chad N. Tindel <ctindel at ieee dot org> @@ -13,98 +18,98 @@ Corrections, HA extensions : 2000/10/03-15 : Reorganized and updated Feb 2005 by Jay Vosburgh Added Sysfs information: 2006/04/24 + - Mitch Williams <mitch.a.williams at intel.com> Introduction ============ - The Linux bonding driver provides a method for aggregating +The Linux bonding driver provides a method for aggregating multiple network interfaces into a single logical "bonded" interface. The behavior of the bonded interfaces depends upon the mode; generally speaking, modes provide either hot standby or load balancing services. Additionally, link integrity monitoring may be performed. - - The bonding driver originally came from Donald Becker's + +The bonding driver originally came from Donald Becker's beowulf patches for kernel 2.0. It has changed quite a bit since, and the original tools from extreme-linux and beowulf sites will not work with this version of the driver. - For new versions of the driver, updated userspace tools, and +For new versions of the driver, updated userspace tools, and who to ask for help, please follow the links at the end of this file. -Table of Contents -================= +.. Table of Contents -1. Bonding Driver Installation + 1. Bonding Driver Installation -2. Bonding Driver Options + 2. Bonding Driver Options -3. Configuring Bonding Devices -3.1 Configuration with Sysconfig Support -3.1.1 Using DHCP with Sysconfig -3.1.2 Configuring Multiple Bonds with Sysconfig -3.2 Configuration with Initscripts Support -3.2.1 Using DHCP with Initscripts -3.2.2 Configuring Multiple Bonds with Initscripts -3.3 Configuring Bonding Manually with Ifenslave -3.3.1 Configuring Multiple Bonds Manually -3.4 Configuring Bonding Manually via Sysfs -3.5 Configuration with Interfaces Support -3.6 Overriding Configuration for Special Cases -3.7 Configuring LACP for 802.3ad mode in a more secure way + 3. Configuring Bonding Devices + 3.1 Configuration with Sysconfig Support + 3.1.1 Using DHCP with Sysconfig + 3.1.2 Configuring Multiple Bonds with Sysconfig + 3.2 Configuration with Initscripts Support + 3.2.1 Using DHCP with Initscripts + 3.2.2 Configuring Multiple Bonds with Initscripts + 3.3 Configuring Bonding Manually with Ifenslave + 3.3.1 Configuring Multiple Bonds Manually + 3.4 Configuring Bonding Manually via Sysfs + 3.5 Configuration with Interfaces Support + 3.6 Overriding Configuration for Special Cases + 3.7 Configuring LACP for 802.3ad mode in a more secure way -4. Querying Bonding Configuration -4.1 Bonding Configuration -4.2 Network Configuration + 4. Querying Bonding Configuration + 4.1 Bonding Configuration + 4.2 Network Configuration -5. Switch Configuration + 5. Switch Configuration -6. 802.1q VLAN Support + 6. 802.1q VLAN Support -7. Link Monitoring -7.1 ARP Monitor Operation -7.2 Configuring Multiple ARP Targets -7.3 MII Monitor Operation + 7. Link Monitoring + 7.1 ARP Monitor Operation + 7.2 Configuring Multiple ARP Targets + 7.3 MII Monitor Operation -8. Potential Trouble Sources -8.1 Adventures in Routing -8.2 Ethernet Device Renaming -8.3 Painfully Slow Or No Failed Link Detection By Miimon + 8. Potential Trouble Sources + 8.1 Adventures in Routing + 8.2 Ethernet Device Renaming + 8.3 Painfully Slow Or No Failed Link Detection By Miimon -9. SNMP agents + 9. SNMP agents -10. Promiscuous mode + 10. Promiscuous mode -11. Configuring Bonding for High Availability -11.1 High Availability in a Single Switch Topology -11.2 High Availability in a Multiple Switch Topology -11.2.1 HA Bonding Mode Selection for Multiple Switch Topology -11.2.2 HA Link Monitoring for Multiple Switch Topology + 11. Configuring Bonding for High Availability + 11.1 High Availability in a Single Switch Topology + 11.2 High Availability in a Multiple Switch Topology + 11.2.1 HA Bonding Mode Selection for Multiple Switch Topology + 11.2.2 HA Link Monitoring for Multiple Switch Topology -12. Configuring Bonding for Maximum Throughput -12.1 Maximum Throughput in a Single Switch Topology -12.1.1 MT Bonding Mode Selection for Single Switch Topology -12.1.2 MT Link Monitoring for Single Switch Topology -12.2 Maximum Throughput in a Multiple Switch Topology -12.2.1 MT Bonding Mode Selection for Multiple Switch Topology -12.2.2 MT Link Monitoring for Multiple Switch Topology + 12. Configuring Bonding for Maximum Throughput + 12.1 Maximum Throughput in a Single Switch Topology + 12.1.1 MT Bonding Mode Selection for Single Switch Topology + 12.1.2 MT Link Monitoring for Single Switch Topology + 12.2 Maximum Throughput in a Multiple Switch Topology + 12.2.1 MT Bonding Mode Selection for Multiple Switch Topology + 12.2.2 MT Link Monitoring for Multiple Switch Topology -13. Switch Behavior Issues -13.1 Link Establishment and Failover Delays -13.2 Duplicated Incoming Packets + 13. Switch Behavior Issues + 13.1 Link Establishment and Failover Delays + 13.2 Duplicated Incoming Packets -14. Hardware Specific Considerations -14.1 IBM BladeCenter + 14. Hardware Specific Considerations + 14.1 IBM BladeCenter -15. Frequently Asked Questions + 15. Frequently Asked Questions -16. Resources and Links + 16. Resources and Links 1. Bonding Driver Installation ============================== - Most popular distro kernels ship with the bonding driver +Most popular distro kernels ship with the bonding driver already available as a module. If your distro does not, or you have need to compile bonding from source (e.g., configuring and installing a mainline kernel from kernel.org), you'll need to perform @@ -113,54 +118,54 @@ the following steps: 1.1 Configure and build the kernel with bonding ----------------------------------------------- - The current version of the bonding driver is available in the +The current version of the bonding driver is available in the drivers/net/bonding subdirectory of the most recent kernel source (which is available on http://kernel.org). Most users "rolling their own" will want to use the most recent kernel from kernel.org. - Configure kernel with "make menuconfig" (or "make xconfig" or +Configure kernel with "make menuconfig" (or "make xconfig" or "make config"), then select "Bonding driver support" in the "Network device support" section. It is recommended that you configure the driver as module since it is currently the only way to pass parameters to the driver or configure more than one bonding device. - Build and install the new kernel and modules. +Build and install the new kernel and modules. 1.2 Bonding Control Utility -------------------------------------- +--------------------------- - It is recommended to configure bonding via iproute2 (netlink) +It is recommended to configure bonding via iproute2 (netlink) or sysfs, the old ifenslave control utility is obsolete. 2. Bonding Driver Options ========================= - Options for the bonding driver are supplied as parameters to the +Options for the bonding driver are supplied as parameters to the bonding module at load time, or are specified via sysfs. - Module options may be given as command line arguments to the +Module options may be given as command line arguments to the insmod or modprobe command, but are usually specified in either the -/etc/modprobe.d/*.conf configuration files, or in a distro-specific +``/etc/modprobe.d/*.conf`` configuration files, or in a distro-specific configuration file (some of which are detailed in the next section). - Details on bonding support for sysfs is provided in the +Details on bonding support for sysfs is provided in the "Configuring Bonding Manually via Sysfs" section, below. - The available bonding driver parameters are listed below. If a +The available bonding driver parameters are listed below. If a parameter is not specified the default value is used. When initially configuring a bond, it is recommended "tail -f /var/log/messages" be run in a separate window to watch for bonding driver error messages. - It is critical that either the miimon or arp_interval and +It is critical that either the miimon or arp_interval and arp_ip_target parameters be specified, otherwise serious network degradation will occur during link failures. Very few devices do not support at least miimon, so there is really no reason not to use it. - Options with textual values will accept either the text name +Options with textual values will accept either the text name or, for backwards compatibility, the option value. E.g., "mode=802.3ad" and "mode=4" set the same mode. - The parameters are as follows: +The parameters are as follows: active_slave @@ -246,10 +251,13 @@ ad_user_port_key In an AD system, the port-key has three parts as shown below - + ===== ============ Bits Use + ===== ============ 00 Duplex 01-05 Speed 06-15 User-defined + ===== ============ This defines the upper 10 bits of the port key. The values can be from 0 - 1023. If not given, the system defaults to 0. @@ -699,7 +707,7 @@ mode swapped with the new curr_active_slave that was chosen. -num_grat_arp +num_grat_arp, num_unsol_na Specify the number of peer notifications (gratuitous ARPs and @@ -729,13 +737,13 @@ packets_per_slave peer_notif_delay - Specify the delay, in milliseconds, between each peer - notification (gratuitous ARP and unsolicited IPv6 Neighbor - Advertisement) when they are issued after a failover event. - This delay should be a multiple of the link monitor interval - (arp_interval or miimon, whichever is active). The default - value is 0 which means to match the value of the link monitor - interval. + Specify the delay, in milliseconds, between each peer + notification (gratuitous ARP and unsolicited IPv6 Neighbor + Advertisement) when they are issued after a failover event. + This delay should be a multiple of the link monitor interval + (arp_interval or miimon, whichever is active). The default + value is 0 which means to match the value of the link monitor + interval. primary @@ -977,88 +985,88 @@ lp_interval 3. Configuring Bonding Devices ============================== - You can configure bonding using either your distro's network +You can configure bonding using either your distro's network initialization scripts, or manually using either iproute2 or the sysfs interface. Distros generally use one of three packages for the network initialization scripts: initscripts, sysconfig or interfaces. Recent versions of these packages have support for bonding, while older versions do not. - We will first describe the options for configuring bonding for +We will first describe the options for configuring bonding for distros using versions of initscripts, sysconfig and interfaces with full or partial support for bonding, then provide information on enabling bonding without support from the network initialization scripts (i.e., older versions of initscripts or sysconfig). - If you're unsure whether your distro uses sysconfig, +If you're unsure whether your distro uses sysconfig, initscripts or interfaces, or don't know if it's new enough, have no fear. Determining this is fairly straightforward. - First, look for a file called interfaces in /etc/network directory. +First, look for a file called interfaces in /etc/network directory. If this file is present in your system, then your system use interfaces. See Configuration with Interfaces Support. - Else, issue the command: +Else, issue the command:: -$ rpm -qf /sbin/ifup + $ rpm -qf /sbin/ifup - It will respond with a line of text starting with either +It will respond with a line of text starting with either "initscripts" or "sysconfig," followed by some numbers. This is the package that provides your network initialization scripts. - Next, to determine if your installation supports bonding, -issue the command: +Next, to determine if your installation supports bonding, +issue the command:: -$ grep ifenslave /sbin/ifup + $ grep ifenslave /sbin/ifup - If this returns any matches, then your initscripts or +If this returns any matches, then your initscripts or sysconfig has support for bonding. 3.1 Configuration with Sysconfig Support ---------------------------------------- - This section applies to distros using a version of sysconfig +This section applies to distros using a version of sysconfig with bonding support, for example, SuSE Linux Enterprise Server 9. - SuSE SLES 9's networking configuration system does support +SuSE SLES 9's networking configuration system does support bonding, however, at this writing, the YaST system configuration front end does not provide any means to work with bonding devices. Bonding devices can be managed by hand, however, as follows. - First, if they have not already been configured, configure the +First, if they have not already been configured, configure the slave devices. On SLES 9, this is most easily done by running the yast2 sysconfig configuration utility. The goal is for to create an ifcfg-id file for each slave device. The simplest way to accomplish this is to configure the devices for DHCP (this is only to get the file ifcfg-id file created; see below for some issues with DHCP). The -name of the configuration file for each device will be of the form: +name of the configuration file for each device will be of the form:: -ifcfg-id-xx:xx:xx:xx:xx:xx + ifcfg-id-xx:xx:xx:xx:xx:xx - Where the "xx" portion will be replaced with the digits from +Where the "xx" portion will be replaced with the digits from the device's permanent MAC address. - Once the set of ifcfg-id-xx:xx:xx:xx:xx:xx files has been +Once the set of ifcfg-id-xx:xx:xx:xx:xx:xx files has been created, it is necessary to edit the configuration files for the slave devices (the MAC addresses correspond to those of the slave devices). Before editing, the file will contain multiple lines, and will look -something like this: +something like this:: -BOOTPROTO='dhcp' -STARTMODE='on' -USERCTL='no' -UNIQUE='XNzu.WeZGOGF+4wE' -_nm_name='bus-pci-0001:61:01.0' + BOOTPROTO='dhcp' + STARTMODE='on' + USERCTL='no' + UNIQUE='XNzu.WeZGOGF+4wE' + _nm_name='bus-pci-0001:61:01.0' - Change the BOOTPROTO and STARTMODE lines to the following: +Change the BOOTPROTO and STARTMODE lines to the following:: -BOOTPROTO='none' -STARTMODE='off' + BOOTPROTO='none' + STARTMODE='off' - Do not alter the UNIQUE or _nm_name lines. Remove any other +Do not alter the UNIQUE or _nm_name lines. Remove any other lines (USERCTL, etc). - Once the ifcfg-id-xx:xx:xx:xx:xx:xx files have been modified, +Once the ifcfg-id-xx:xx:xx:xx:xx:xx files have been modified, it's time to create the configuration file for the bonding device itself. This file is named ifcfg-bondX, where X is the number of the bonding device to create, starting at 0. The first such file is @@ -1066,49 +1074,52 @@ ifcfg-bond0, the second is ifcfg-bond1, and so on. The sysconfig network configuration system will correctly start multiple instances of bonding. - The contents of the ifcfg-bondX file is as follows: - -BOOTPROTO="static" -BROADCAST="10.0.2.255" -IPADDR="10.0.2.10" -NETMASK="255.255.0.0" -NETWORK="10.0.2.0" -REMOTE_IPADDR="" -STARTMODE="onboot" -BONDING_MASTER="yes" -BONDING_MODULE_OPTS="mode=active-backup miimon=100" -BONDING_SLAVE0="eth0" -BONDING_SLAVE1="bus-pci-0000:06:08.1" - - Replace the sample BROADCAST, IPADDR, NETMASK and NETWORK +The contents of the ifcfg-bondX file is as follows:: + + BOOTPROTO="static" + BROADCAST="10.0.2.255" + IPADDR="10.0.2.10" + NETMASK="255.255.0.0" + NETWORK="10.0.2.0" + REMOTE_IPADDR="" + STARTMODE="onboot" + BONDING_MASTER="yes" + BONDING_MODULE_OPTS="mode=active-backup miimon=100" + BONDING_SLAVE0="eth0" + BONDING_SLAVE1="bus-pci-0000:06:08.1" + +Replace the sample BROADCAST, IPADDR, NETMASK and NETWORK values with the appropriate values for your network. - The STARTMODE specifies when the device is brought online. +The STARTMODE specifies when the device is brought online. The possible values are: - onboot: The device is started at boot time. If you're not + ======== ====================================================== + onboot The device is started at boot time. If you're not sure, this is probably what you want. - manual: The device is started only when ifup is called + manual The device is started only when ifup is called manually. Bonding devices may be configured this way if you do not wish them to start automatically at boot for some reason. - hotplug: The device is started by a hotplug event. This is not + hotplug The device is started by a hotplug event. This is not a valid choice for a bonding device. - off or ignore: The device configuration is ignored. + off or The device configuration is ignored. + ignore + ======== ====================================================== - The line BONDING_MASTER='yes' indicates that the device is a +The line BONDING_MASTER='yes' indicates that the device is a bonding master device. The only useful value is "yes." - The contents of BONDING_MODULE_OPTS are supplied to the +The contents of BONDING_MODULE_OPTS are supplied to the instance of the bonding module for this device. Specify the options for the bonding mode, link monitoring, and so on here. Do not include the max_bonds bonding parameter; this will confuse the configuration system if you have multiple bonding devices. - Finally, supply one BONDING_SLAVEn="slave device" for each +Finally, supply one BONDING_SLAVEn="slave device" for each slave. where "n" is an increasing value, one for each slave. The "slave device" is either an interface name, e.g., "eth0", or a device specifier for the network device. The interface name is easier to @@ -1120,34 +1131,34 @@ changes (for example, it is moved from one PCI slot to another). The example above uses one of each type for demonstration purposes; most configurations will choose one or the other for all slave devices. - When all configuration files have been modified or created, +When all configuration files have been modified or created, networking must be restarted for the configuration changes to take -effect. This can be accomplished via the following: +effect. This can be accomplished via the following:: -# /etc/init.d/network restart + # /etc/init.d/network restart - Note that the network control script (/sbin/ifdown) will +Note that the network control script (/sbin/ifdown) will remove the bonding module as part of the network shutdown processing, so it is not necessary to remove the module by hand if, e.g., the module parameters have changed. - Also, at this writing, YaST/YaST2 will not manage bonding +Also, at this writing, YaST/YaST2 will not manage bonding devices (they do not show bonding interfaces on its list of network devices). It is necessary to edit the configuration file by hand to change the bonding configuration. - Additional general options and details of the ifcfg file -format can be found in an example ifcfg template file: +Additional general options and details of the ifcfg file +format can be found in an example ifcfg template file:: -/etc/sysconfig/network/ifcfg.template + /etc/sysconfig/network/ifcfg.template - Note that the template does not document the various BONDING_ +Note that the template does not document the various ``BONDING_*`` settings described above, but does describe many of the other options. 3.1.1 Using DHCP with Sysconfig ------------------------------- - Under sysconfig, configuring a device with BOOTPROTO='dhcp' +Under sysconfig, configuring a device with BOOTPROTO='dhcp' will cause it to query DHCP for its IP address information. At this writing, this does not function for bonding devices; the scripts attempt to obtain the device address from DHCP prior to adding any of @@ -1157,7 +1168,7 @@ sent to the network. 3.1.2 Configuring Multiple Bonds with Sysconfig ----------------------------------------------- - The sysconfig network initialization system is capable of +The sysconfig network initialization system is capable of handling multiple bonding devices. All that is necessary is for each bonding instance to have an appropriately configured ifcfg-bondX file (as described above). Do not specify the "max_bonds" parameter to any @@ -1165,14 +1176,14 @@ instance of bonding, as this will confuse sysconfig. If you require multiple bonding devices with identical parameters, create multiple ifcfg-bondX files. - Because the sysconfig scripts supply the bonding module +Because the sysconfig scripts supply the bonding module options in the ifcfg-bondX file, it is not necessary to add them to -the system /etc/modules.d/*.conf configuration files. +the system ``/etc/modules.d/*.conf`` configuration files. 3.2 Configuration with Initscripts Support ------------------------------------------ - This section applies to distros using a recent version of +This section applies to distros using a recent version of initscripts with bonding support, for example, Red Hat Enterprise Linux version 3 or later, Fedora, etc. On these systems, the network initialization scripts have knowledge of bonding, and can be configured to @@ -1180,7 +1191,7 @@ control bonding devices. Note that older versions of the initscripts package have lower levels of support for bonding; this will be noted where applicable. - These distros will not automatically load the network adapter +These distros will not automatically load the network adapter driver unless the ethX device is configured with an IP address. Because of this constraint, users must manually configure a network-script file for all physical adapters that will be members of @@ -1188,19 +1199,19 @@ a bondX link. Network script files are located in the directory: /etc/sysconfig/network-scripts - The file name must be prefixed with "ifcfg-eth" and suffixed +The file name must be prefixed with "ifcfg-eth" and suffixed with the adapter's physical adapter number. For example, the script for eth0 would be named /etc/sysconfig/network-scripts/ifcfg-eth0. -Place the following text in the file: +Place the following text in the file:: -DEVICE=eth0 -USERCTL=no -ONBOOT=yes -MASTER=bond0 -SLAVE=yes -BOOTPROTO=none + DEVICE=eth0 + USERCTL=no + ONBOOT=yes + MASTER=bond0 + SLAVE=yes + BOOTPROTO=none - The DEVICE= line will be different for every ethX device and +The DEVICE= line will be different for every ethX device and must correspond with the name of the file, i.e., ifcfg-eth1 must have a device line of DEVICE=eth1. The setting of the MASTER= line will also depend on the final bonding interface name chosen for your bond. @@ -1208,69 +1219,70 @@ As with other network devices, these typically start at 0, and go up one for each device, i.e., the first bonding instance is bond0, the second is bond1, and so on. - Next, create a bond network script. The file name for this +Next, create a bond network script. The file name for this script will be /etc/sysconfig/network-scripts/ifcfg-bondX where X is the number of the bond. For bond0 the file is named "ifcfg-bond0", for bond1 it is named "ifcfg-bond1", and so on. Within that file, -place the following text: - -DEVICE=bond0 -IPADDR=192.168.1.1 -NETMASK=255.255.255.0 -NETWORK=192.168.1.0 -BROADCAST=192.168.1.255 -ONBOOT=yes -BOOTPROTO=none -USERCTL=no - - Be sure to change the networking specific lines (IPADDR, +place the following text:: + + DEVICE=bond0 + IPADDR=192.168.1.1 + NETMASK=255.255.255.0 + NETWORK=192.168.1.0 + BROADCAST=192.168.1.255 + ONBOOT=yes + BOOTPROTO=none + USERCTL=no + +Be sure to change the networking specific lines (IPADDR, NETMASK, NETWORK and BROADCAST) to match your network configuration. - For later versions of initscripts, such as that found with Fedora +For later versions of initscripts, such as that found with Fedora 7 (or later) and Red Hat Enterprise Linux version 5 (or later), it is possible, and, indeed, preferable, to specify the bonding options in the ifcfg-bond0 -file, e.g. a line of the format: +file, e.g. a line of the format:: -BONDING_OPTS="mode=active-backup arp_interval=60 arp_ip_target=192.168.1.254" + BONDING_OPTS="mode=active-backup arp_interval=60 arp_ip_target=192.168.1.254" - will configure the bond with the specified options. The options +will configure the bond with the specified options. The options specified in BONDING_OPTS are identical to the bonding module parameters except for the arp_ip_target field when using versions of initscripts older than and 8.57 (Fedora 8) and 8.45.19 (Red Hat Enterprise Linux 5.2). When using older versions each target should be included as a separate option and should be preceded by a '+' to indicate it should be added to the list of -queried targets, e.g., +queried targets, e.g.,:: - arp_ip_target=+192.168.1.1 arp_ip_target=+192.168.1.2 + arp_ip_target=+192.168.1.1 arp_ip_target=+192.168.1.2 - is the proper syntax to specify multiple targets. When specifying -options via BONDING_OPTS, it is not necessary to edit /etc/modprobe.d/*.conf. +is the proper syntax to specify multiple targets. When specifying +options via BONDING_OPTS, it is not necessary to edit +``/etc/modprobe.d/*.conf``. - For even older versions of initscripts that do not support +For even older versions of initscripts that do not support BONDING_OPTS, it is necessary to edit /etc/modprobe.d/*.conf, depending upon your distro) to load the bonding module with your desired options when the bond0 interface is brought up. The following lines in /etc/modprobe.d/*.conf will load the bonding module, and select its options: -alias bond0 bonding -options bond0 mode=balance-alb miimon=100 + alias bond0 bonding + options bond0 mode=balance-alb miimon=100 - Replace the sample parameters with the appropriate set of +Replace the sample parameters with the appropriate set of options for your configuration. - Finally run "/etc/rc.d/init.d/network restart" as root. This +Finally run "/etc/rc.d/init.d/network restart" as root. This will restart the networking subsystem and your bond link should be now up and running. 3.2.1 Using DHCP with Initscripts --------------------------------- - Recent versions of initscripts (the versions supplied with Fedora +Recent versions of initscripts (the versions supplied with Fedora Core 3 and Red Hat Enterprise Linux 4, or later versions, are reported to work) have support for assigning IP information to bonding devices via DHCP. - To configure bonding for DHCP, configure it as described +To configure bonding for DHCP, configure it as described above, except replace the line "BOOTPROTO=none" with "BOOTPROTO=dhcp" and add a line consisting of "TYPE=Bonding". Note that the TYPE value is case sensitive. @@ -1278,7 +1290,7 @@ is case sensitive. 3.2.2 Configuring Multiple Bonds with Initscripts ------------------------------------------------- - Initscripts packages that are included with Fedora 7 and Red Hat +Initscripts packages that are included with Fedora 7 and Red Hat Enterprise Linux 5 support multiple bonding interfaces by simply specifying the appropriate BONDING_OPTS= in ifcfg-bondX where X is the number of the bond. This support requires sysfs support in the kernel, @@ -1290,77 +1302,77 @@ below. 3.3 Configuring Bonding Manually with iproute2 ----------------------------------------------- - This section applies to distros whose network initialization +This section applies to distros whose network initialization scripts (the sysconfig or initscripts package) do not have specific knowledge of bonding. One such distro is SuSE Linux Enterprise Server version 8. - The general method for these systems is to place the bonding +The general method for these systems is to place the bonding module parameters into a config file in /etc/modprobe.d/ (as appropriate for the installed distro), then add modprobe and/or `ip link` commands to the system's global init script. The name of the global init script differs; for sysconfig, it is /etc/init.d/boot.local and for initscripts it is /etc/rc.d/rc.local. - For example, if you wanted to make a simple bond of two e100 +For example, if you wanted to make a simple bond of two e100 devices (presumed to be eth0 and eth1), and have it persist across reboots, edit the appropriate file (/etc/init.d/boot.local or -/etc/rc.d/rc.local), and add the following: +/etc/rc.d/rc.local), and add the following:: -modprobe bonding mode=balance-alb miimon=100 -modprobe e100 -ifconfig bond0 192.168.1.1 netmask 255.255.255.0 up -ip link set eth0 master bond0 -ip link set eth1 master bond0 + modprobe bonding mode=balance-alb miimon=100 + modprobe e100 + ifconfig bond0 192.168.1.1 netmask 255.255.255.0 up + ip link set eth0 master bond0 + ip link set eth1 master bond0 - Replace the example bonding module parameters and bond0 +Replace the example bonding module parameters and bond0 network configuration (IP address, netmask, etc) with the appropriate values for your configuration. - Unfortunately, this method will not provide support for the +Unfortunately, this method will not provide support for the ifup and ifdown scripts on the bond devices. To reload the bonding -configuration, it is necessary to run the initialization script, e.g., +configuration, it is necessary to run the initialization script, e.g.,:: -# /etc/init.d/boot.local + # /etc/init.d/boot.local - or +or:: -# /etc/rc.d/rc.local + # /etc/rc.d/rc.local - It may be desirable in such a case to create a separate script +It may be desirable in such a case to create a separate script which only initializes the bonding configuration, then call that separate script from within boot.local. This allows for bonding to be enabled without re-running the entire global init script. - To shut down the bonding devices, it is necessary to first +To shut down the bonding devices, it is necessary to first mark the bonding device itself as being down, then remove the appropriate device driver modules. For our example above, you can do -the following: +the following:: -# ifconfig bond0 down -# rmmod bonding -# rmmod e100 + # ifconfig bond0 down + # rmmod bonding + # rmmod e100 - Again, for convenience, it may be desirable to create a script +Again, for convenience, it may be desirable to create a script with these commands. 3.3.1 Configuring Multiple Bonds Manually ----------------------------------------- - This section contains information on configuring multiple +This section contains information on configuring multiple bonding devices with differing options for those systems whose network initialization scripts lack support for configuring multiple bonds. - If you require multiple bonding devices, but all with the same +If you require multiple bonding devices, but all with the same options, you may wish to use the "max_bonds" module parameter, documented above. - To create multiple bonding devices with differing options, it is +To create multiple bonding devices with differing options, it is preferable to use bonding parameters exported by sysfs, documented in the section below. - For versions of bonding without sysfs support, the only means to +For versions of bonding without sysfs support, the only means to provide multiple instances of bonding with differing options is to load the bonding driver multiple times. Note that current versions of the sysconfig network initialization scripts handle this automatically; if @@ -1368,35 +1380,35 @@ your distro uses these scripts, no special action is needed. See the section Configuring Bonding Devices, above, if you're not sure about your network initialization scripts. - To load multiple instances of the module, it is necessary to +To load multiple instances of the module, it is necessary to specify a different name for each instance (the module loading system requires that every loaded module, even multiple instances of the same module, have a unique name). This is accomplished by supplying multiple -sets of bonding options in /etc/modprobe.d/*.conf, for example: +sets of bonding options in ``/etc/modprobe.d/*.conf``, for example:: -alias bond0 bonding -options bond0 -o bond0 mode=balance-rr miimon=100 + alias bond0 bonding + options bond0 -o bond0 mode=balance-rr miimon=100 -alias bond1 bonding -options bond1 -o bond1 mode=balance-alb miimon=50 + alias bond1 bonding + options bond1 -o bond1 mode=balance-alb miimon=50 - will load the bonding module two times. The first instance is +will load the bonding module two times. The first instance is named "bond0" and creates the bond0 device in balance-rr mode with an miimon of 100. The second instance is named "bond1" and creates the bond1 device in balance-alb mode with an miimon of 50. - In some circumstances (typically with older distributions), +In some circumstances (typically with older distributions), the above does not work, and the second bonding instance never sees its options. In that case, the second options line can be substituted -as follows: +as follows:: -install bond1 /sbin/modprobe --ignore-install bonding -o bond1 \ - mode=balance-alb miimon=50 + install bond1 /sbin/modprobe --ignore-install bonding -o bond1 \ + mode=balance-alb miimon=50 - This may be repeated any number of times, specifying a new and +This may be repeated any number of times, specifying a new and unique name in place of bond1 for each subsequent instance. - It has been observed that some Red Hat supplied kernels are unable +It has been observed that some Red Hat supplied kernels are unable to rename modules at load time (the "-o bond1" part). Attempts to pass that option to modprobe will produce an "Operation not permitted" error. This has been reported on some Fedora Core kernels, and has been seen on @@ -1407,18 +1419,18 @@ kernels, and also lack sysfs support). 3.4 Configuring Bonding Manually via Sysfs ------------------------------------------ - Starting with version 3.0.0, Channel Bonding may be configured +Starting with version 3.0.0, Channel Bonding may be configured via the sysfs interface. This interface allows dynamic configuration of all bonds in the system without unloading the module. It also allows for adding and removing bonds at runtime. Ifenslave is no longer required, though it is still supported. - Use of the sysfs interface allows you to use multiple bonds +Use of the sysfs interface allows you to use multiple bonds with different configurations without having to reload the module. It also allows you to use multiple, differently configured bonds when bonding is compiled into the kernel. - You must have the sysfs filesystem mounted to configure +You must have the sysfs filesystem mounted to configure bonding this way. The examples in this document assume that you are using the standard mount point for sysfs, e.g. /sys. If your sysfs filesystem is mounted elsewhere, you will need to adjust the @@ -1426,38 +1438,45 @@ example paths accordingly. Creating and Destroying Bonds ----------------------------- -To add a new bond foo: -# echo +foo > /sys/class/net/bonding_masters +To add a new bond foo:: + + # echo +foo > /sys/class/net/bonding_masters + +To remove an existing bond bar:: -To remove an existing bond bar: -# echo -bar > /sys/class/net/bonding_masters + # echo -bar > /sys/class/net/bonding_masters -To show all existing bonds: -# cat /sys/class/net/bonding_masters +To show all existing bonds:: -NOTE: due to 4K size limitation of sysfs files, this list may be -truncated if you have more than a few hundred bonds. This is unlikely -to occur under normal operating conditions. + # cat /sys/class/net/bonding_masters + +.. note:: + + due to 4K size limitation of sysfs files, this list may be + truncated if you have more than a few hundred bonds. This is unlikely + to occur under normal operating conditions. Adding and Removing Slaves -------------------------- - Interfaces may be enslaved to a bond using the file +Interfaces may be enslaved to a bond using the file /sys/class/net/<bond>/bonding/slaves. The semantics for this file are the same as for the bonding_masters file. -To enslave interface eth0 to bond bond0: -# ifconfig bond0 up -# echo +eth0 > /sys/class/net/bond0/bonding/slaves +To enslave interface eth0 to bond bond0:: + + # ifconfig bond0 up + # echo +eth0 > /sys/class/net/bond0/bonding/slaves -To free slave eth0 from bond bond0: -# echo -eth0 > /sys/class/net/bond0/bonding/slaves +To free slave eth0 from bond bond0:: - When an interface is enslaved to a bond, symlinks between the + # echo -eth0 > /sys/class/net/bond0/bonding/slaves + +When an interface is enslaved to a bond, symlinks between the two are created in the sysfs filesystem. In this case, you would get /sys/class/net/bond0/slave_eth0 pointing to /sys/class/net/eth0, and /sys/class/net/eth0/master pointing to /sys/class/net/bond0. - This means that you can tell quickly whether or not an +This means that you can tell quickly whether or not an interface is enslaved by looking for the master symlink. Thus: # echo -eth0 > /sys/class/net/eth0/master/bonding/slaves will free eth0 from whatever bond it is enslaved to, regardless of @@ -1465,127 +1484,143 @@ the name of the bond interface. Changing a Bond's Configuration ------------------------------- - Each bond may be configured individually by manipulating the +Each bond may be configured individually by manipulating the files located in /sys/class/net/<bond name>/bonding - The names of these files correspond directly with the command- +The names of these files correspond directly with the command- line parameters described elsewhere in this file, and, with the exception of arp_ip_target, they accept the same values. To see the current setting, simply cat the appropriate file. - A few examples will be given here; for specific usage +A few examples will be given here; for specific usage guidelines for each parameter, see the appropriate section in this document. -To configure bond0 for balance-alb mode: -# ifconfig bond0 down -# echo 6 > /sys/class/net/bond0/bonding/mode - - or - -# echo balance-alb > /sys/class/net/bond0/bonding/mode - NOTE: The bond interface must be down before the mode can be -changed. - -To enable MII monitoring on bond0 with a 1 second interval: -# echo 1000 > /sys/class/net/bond0/bonding/miimon - NOTE: If ARP monitoring is enabled, it will disabled when MII -monitoring is enabled, and vice-versa. - -To add ARP targets: -# echo +192.168.0.100 > /sys/class/net/bond0/bonding/arp_ip_target -# echo +192.168.0.101 > /sys/class/net/bond0/bonding/arp_ip_target - NOTE: up to 16 target addresses may be specified. - -To remove an ARP target: -# echo -192.168.0.100 > /sys/class/net/bond0/bonding/arp_ip_target - -To configure the interval between learning packet transmits: -# echo 12 > /sys/class/net/bond0/bonding/lp_interval - NOTE: the lp_interval is the number of seconds between instances where -the bonding driver sends learning packets to each slaves peer switch. The -default interval is 1 second. +To configure bond0 for balance-alb mode:: + + # ifconfig bond0 down + # echo 6 > /sys/class/net/bond0/bonding/mode + - or - + # echo balance-alb > /sys/class/net/bond0/bonding/mode + +.. note:: + + The bond interface must be down before the mode can be changed. + +To enable MII monitoring on bond0 with a 1 second interval:: + + # echo 1000 > /sys/class/net/bond0/bonding/miimon + +.. note:: + + If ARP monitoring is enabled, it will disabled when MII + monitoring is enabled, and vice-versa. + +To add ARP targets:: + + # echo +192.168.0.100 > /sys/class/net/bond0/bonding/arp_ip_target + # echo +192.168.0.101 > /sys/class/net/bond0/bonding/arp_ip_target + +.. note:: + + up to 16 target addresses may be specified. + +To remove an ARP target:: + + # echo -192.168.0.100 > /sys/class/net/bond0/bonding/arp_ip_target + +To configure the interval between learning packet transmits:: + + # echo 12 > /sys/class/net/bond0/bonding/lp_interval + +.. note:: + + the lp_interval is the number of seconds between instances where + the bonding driver sends learning packets to each slaves peer switch. The + default interval is 1 second. Example Configuration --------------------- - We begin with the same example that is shown in section 3.3, +We begin with the same example that is shown in section 3.3, executed with sysfs, and without using ifenslave. - To make a simple bond of two e100 devices (presumed to be eth0 +To make a simple bond of two e100 devices (presumed to be eth0 and eth1), and have it persist across reboots, edit the appropriate file (/etc/init.d/boot.local or /etc/rc.d/rc.local), and add the -following: +following:: -modprobe bonding -modprobe e100 -echo balance-alb > /sys/class/net/bond0/bonding/mode -ifconfig bond0 192.168.1.1 netmask 255.255.255.0 up -echo 100 > /sys/class/net/bond0/bonding/miimon -echo +eth0 > /sys/class/net/bond0/bonding/slaves -echo +eth1 > /sys/class/net/bond0/bonding/slaves + modprobe bonding + modprobe e100 + echo balance-alb > /sys/class/net/bond0/bonding/mode + ifconfig bond0 192.168.1.1 netmask 255.255.255.0 up + echo 100 > /sys/class/net/bond0/bonding/miimon + echo +eth0 > /sys/class/net/bond0/bonding/slaves + echo +eth1 > /sys/class/net/bond0/bonding/slaves - To add a second bond, with two e1000 interfaces in +To add a second bond, with two e1000 interfaces in active-backup mode, using ARP monitoring, add the following lines to -your init script: +your init script:: -modprobe e1000 -echo +bond1 > /sys/class/net/bonding_masters -echo active-backup > /sys/class/net/bond1/bonding/mode -ifconfig bond1 192.168.2.1 netmask 255.255.255.0 up -echo +192.168.2.100 /sys/class/net/bond1/bonding/arp_ip_target -echo 2000 > /sys/class/net/bond1/bonding/arp_interval -echo +eth2 > /sys/class/net/bond1/bonding/slaves -echo +eth3 > /sys/class/net/bond1/bonding/slaves + modprobe e1000 + echo +bond1 > /sys/class/net/bonding_masters + echo active-backup > /sys/class/net/bond1/bonding/mode + ifconfig bond1 192.168.2.1 netmask 255.255.255.0 up + echo +192.168.2.100 /sys/class/net/bond1/bonding/arp_ip_target + echo 2000 > /sys/class/net/bond1/bonding/arp_interval + echo +eth2 > /sys/class/net/bond1/bonding/slaves + echo +eth3 > /sys/class/net/bond1/bonding/slaves 3.5 Configuration with Interfaces Support ----------------------------------------- - This section applies to distros which use /etc/network/interfaces file +This section applies to distros which use /etc/network/interfaces file to describe network interface configuration, most notably Debian and it's derivatives. - The ifup and ifdown commands on Debian don't support bonding out of +The ifup and ifdown commands on Debian don't support bonding out of the box. The ifenslave-2.6 package should be installed to provide bonding -support. Once installed, this package will provide bond-* options to be used -into /etc/network/interfaces. +support. Once installed, this package will provide ``bond-*`` options +to be used into /etc/network/interfaces. - Note that ifenslave-2.6 package will load the bonding module and use +Note that ifenslave-2.6 package will load the bonding module and use the ifenslave command when appropriate. Example Configurations ---------------------- In /etc/network/interfaces, the following stanza will configure bond0, in -active-backup mode, with eth0 and eth1 as slaves. +active-backup mode, with eth0 and eth1 as slaves:: -auto bond0 -iface bond0 inet dhcp - bond-slaves eth0 eth1 - bond-mode active-backup - bond-miimon 100 - bond-primary eth0 eth1 + auto bond0 + iface bond0 inet dhcp + bond-slaves eth0 eth1 + bond-mode active-backup + bond-miimon 100 + bond-primary eth0 eth1 If the above configuration doesn't work, you might have a system using upstart for system startup. This is most notably true for recent Ubuntu versions. The following stanza in /etc/network/interfaces will -produce the same result on those systems. - -auto bond0 -iface bond0 inet dhcp - bond-slaves none - bond-mode active-backup - bond-miimon 100 - -auto eth0 -iface eth0 inet manual - bond-master bond0 - bond-primary eth0 eth1 - -auto eth1 -iface eth1 inet manual - bond-master bond0 - bond-primary eth0 eth1 - -For a full list of bond-* supported options in /etc/network/interfaces and some -more advanced examples tailored to you particular distros, see the files in +produce the same result on those systems:: + + auto bond0 + iface bond0 inet dhcp + bond-slaves none + bond-mode active-backup + bond-miimon 100 + + auto eth0 + iface eth0 inet manual + bond-master bond0 + bond-primary eth0 eth1 + + auto eth1 + iface eth1 inet manual + bond-master bond0 + bond-primary eth0 eth1 + +For a full list of ``bond-*`` supported options in /etc/network/interfaces and +some more advanced examples tailored to you particular distros, see the files in /usr/share/doc/ifenslave-2.6. 3.6 Overriding Configuration for Special Cases @@ -1610,31 +1645,31 @@ tx_queues can be used to change this value. There is no sysfs parameter available as the allocation is done at module init time. The output of the file /proc/net/bonding/bondX has changed so the output Queue -ID is now printed for each slave: +ID is now printed for each slave:: -Bonding Mode: fault-tolerance (active-backup) -Primary Slave: None -Currently Active Slave: eth0 -MII Status: up -MII Polling Interval (ms): 0 -Up Delay (ms): 0 -Down Delay (ms): 0 + Bonding Mode: fault-tolerance (active-backup) + Primary Slave: None + Currently Active Slave: eth0 + MII Status: up + MII Polling Interval (ms): 0 + Up Delay (ms): 0 + Down Delay (ms): 0 -Slave Interface: eth0 -MII Status: up -Link Failure Count: 0 -Permanent HW addr: 00:1a:a0:12:8f:cb -Slave queue ID: 0 + Slave Interface: eth0 + MII Status: up + Link Failure Count: 0 + Permanent HW addr: 00:1a:a0:12:8f:cb + Slave queue ID: 0 -Slave Interface: eth1 -MII Status: up -Link Failure Count: 0 -Permanent HW addr: 00:1a:a0:12:8f:cc -Slave queue ID: 2 + Slave Interface: eth1 + MII Status: up + Link Failure Count: 0 + Permanent HW addr: 00:1a:a0:12:8f:cc + Slave queue ID: 2 -The queue_id for a slave can be set using the command: +The queue_id for a slave can be set using the command:: -# echo "eth1:2" > /sys/class/net/bond0/bonding/queue_id + # echo "eth1:2" > /sys/class/net/bond0/bonding/queue_id Any interface that needs a queue_id set should set it with multiple calls like the one above until proper priorities are set for all interfaces. On @@ -1645,12 +1680,12 @@ These queue id's can be used in conjunction with the tc utility to configure a multiqueue qdisc and filters to bias certain traffic to transmit on certain slave devices. For instance, say we wanted, in the above configuration to force all traffic bound to 192.168.1.100 to use eth1 in the bond as its output -device. The following commands would accomplish this: +device. The following commands would accomplish this:: -# tc qdisc add dev bond0 handle 1 root multiq + # tc qdisc add dev bond0 handle 1 root multiq -# tc filter add dev bond0 protocol ip parent 1: prio 1 u32 match ip dst \ - 192.168.1.100 action skbedit queue_mapping 2 + # tc filter add dev bond0 protocol ip parent 1: prio 1 u32 match ip \ + dst 192.168.1.100 action skbedit queue_mapping 2 These commands tell the kernel to attach a multiqueue queue discipline to the bond0 interface and filter traffic enqueued to it, such that packets with a dst @@ -1663,7 +1698,7 @@ that normal output policy selection should take place. One benefit to simply leaving the qid for a slave to 0 is the multiqueue awareness in the bonding driver that is now present. This awareness allows tc filters to be placed on slave devices as well as bond devices and the bonding driver will simply act as -a pass-through for selecting output queues on the slave device rather than +a pass-through for selecting output queues on the slave device rather than output port selection. This feature first appeared in bonding driver version 3.7.0 and support for @@ -1689,31 +1724,31 @@ few bonding parameters: (a) ad_actor_system : You can set a random mac-address that can be used for these LACPDU exchanges. The value can not be either NULL or Multicast. Also it's preferable to set the local-admin bit. Following shell code - generates a random mac-address as described above. + generates a random mac-address as described above:: - # sys_mac_addr=$(printf '%02x:%02x:%02x:%02x:%02x:%02x' \ - $(( (RANDOM & 0xFE) | 0x02 )) \ - $(( RANDOM & 0xFF )) \ - $(( RANDOM & 0xFF )) \ - $(( RANDOM & 0xFF )) \ - $(( RANDOM & 0xFF )) \ - $(( RANDOM & 0xFF ))) - # echo $sys_mac_addr > /sys/class/net/bond0/bonding/ad_actor_system + # sys_mac_addr=$(printf '%02x:%02x:%02x:%02x:%02x:%02x' \ + $(( (RANDOM & 0xFE) | 0x02 )) \ + $(( RANDOM & 0xFF )) \ + $(( RANDOM & 0xFF )) \ + $(( RANDOM & 0xFF )) \ + $(( RANDOM & 0xFF )) \ + $(( RANDOM & 0xFF ))) + # echo $sys_mac_addr > /sys/class/net/bond0/bonding/ad_actor_system (b) ad_actor_sys_prio : Randomize the system priority. The default value is 65535, but system can take the value from 1 - 65535. Following shell - code generates random priority and sets it. + code generates random priority and sets it:: - # sys_prio=$(( 1 + RANDOM + RANDOM )) - # echo $sys_prio > /sys/class/net/bond0/bonding/ad_actor_sys_prio + # sys_prio=$(( 1 + RANDOM + RANDOM )) + # echo $sys_prio > /sys/class/net/bond0/bonding/ad_actor_sys_prio (c) ad_user_port_key : Use the user portion of the port-key. The default keeps this empty. These are the upper 10 bits of the port-key and value ranges from 0 - 1023. Following shell code generates these 10 bits and - sets it. + sets it:: - # usr_port_key=$(( RANDOM & 0x3FF )) - # echo $usr_port_key > /sys/class/net/bond0/bonding/ad_user_port_key + # usr_port_key=$(( RANDOM & 0x3FF )) + # echo $usr_port_key > /sys/class/net/bond0/bonding/ad_user_port_key 4 Querying Bonding Configuration @@ -1722,81 +1757,81 @@ few bonding parameters: 4.1 Bonding Configuration ------------------------- - Each bonding device has a read-only file residing in the +Each bonding device has a read-only file residing in the /proc/net/bonding directory. The file contents include information about the bonding configuration, options and state of each slave. - For example, the contents of /proc/net/bonding/bond0 after the +For example, the contents of /proc/net/bonding/bond0 after the driver is loaded with parameters of mode=0 and miimon=1000 is -generally as follows: +generally as follows:: Ethernet Channel Bonding Driver: 2.6.1 (October 29, 2004) - Bonding Mode: load balancing (round-robin) - Currently Active Slave: eth0 - MII Status: up - MII Polling Interval (ms): 1000 - Up Delay (ms): 0 - Down Delay (ms): 0 - - Slave Interface: eth1 - MII Status: up - Link Failure Count: 1 - - Slave Interface: eth0 - MII Status: up - Link Failure Count: 1 - - The precise format and contents will change depending upon the + Bonding Mode: load balancing (round-robin) + Currently Active Slave: eth0 + MII Status: up + MII Polling Interval (ms): 1000 + Up Delay (ms): 0 + Down Delay (ms): 0 + + Slave Interface: eth1 + MII Status: up + Link Failure Count: 1 + + Slave Interface: eth0 + MII Status: up + Link Failure Count: 1 + +The precise format and contents will change depending upon the bonding configuration, state, and version of the bonding driver. 4.2 Network configuration ------------------------- - The network configuration can be inspected using the ifconfig +The network configuration can be inspected using the ifconfig command. Bonding devices will have the MASTER flag set; Bonding slave devices will have the SLAVE flag set. The ifconfig output does not contain information on which slaves are associated with which masters. - In the example below, the bond0 interface is the master +In the example below, the bond0 interface is the master (MASTER) while eth0 and eth1 are slaves (SLAVE). Notice all slaves of bond0 have the same MAC address (HWaddr) as bond0 for all modes except -TLB and ALB that require a unique MAC address for each slave. - -# /sbin/ifconfig -bond0 Link encap:Ethernet HWaddr 00:C0:F0:1F:37:B4 - inet addr:XXX.XXX.XXX.YYY Bcast:XXX.XXX.XXX.255 Mask:255.255.252.0 - UP BROADCAST RUNNING MASTER MULTICAST MTU:1500 Metric:1 - RX packets:7224794 errors:0 dropped:0 overruns:0 frame:0 - TX packets:3286647 errors:1 dropped:0 overruns:1 carrier:0 - collisions:0 txqueuelen:0 - -eth0 Link encap:Ethernet HWaddr 00:C0:F0:1F:37:B4 - UP BROADCAST RUNNING SLAVE MULTICAST MTU:1500 Metric:1 - RX packets:3573025 errors:0 dropped:0 overruns:0 frame:0 - TX packets:1643167 errors:1 dropped:0 overruns:1 carrier:0 - collisions:0 txqueuelen:100 - Interrupt:10 Base address:0x1080 - -eth1 Link encap:Ethernet HWaddr 00:C0:F0:1F:37:B4 - UP BROADCAST RUNNING SLAVE MULTICAST MTU:1500 Metric:1 - RX packets:3651769 errors:0 dropped:0 overruns:0 frame:0 - TX packets:1643480 errors:0 dropped:0 overruns:0 carrier:0 - collisions:0 txqueuelen:100 - Interrupt:9 Base address:0x1400 +TLB and ALB that require a unique MAC address for each slave:: + + # /sbin/ifconfig + bond0 Link encap:Ethernet HWaddr 00:C0:F0:1F:37:B4 + inet addr:XXX.XXX.XXX.YYY Bcast:XXX.XXX.XXX.255 Mask:255.255.252.0 + UP BROADCAST RUNNING MASTER MULTICAST MTU:1500 Metric:1 + RX packets:7224794 errors:0 dropped:0 overruns:0 frame:0 + TX packets:3286647 errors:1 dropped:0 overruns:1 carrier:0 + collisions:0 txqueuelen:0 + + eth0 Link encap:Ethernet HWaddr 00:C0:F0:1F:37:B4 + UP BROADCAST RUNNING SLAVE MULTICAST MTU:1500 Metric:1 + RX packets:3573025 errors:0 dropped:0 overruns:0 frame:0 + TX packets:1643167 errors:1 dropped:0 overruns:1 carrier:0 + collisions:0 txqueuelen:100 + Interrupt:10 Base address:0x1080 + + eth1 Link encap:Ethernet HWaddr 00:C0:F0:1F:37:B4 + UP BROADCAST RUNNING SLAVE MULTICAST MTU:1500 Metric:1 + RX packets:3651769 errors:0 dropped:0 overruns:0 frame:0 + TX packets:1643480 errors:0 dropped:0 overruns:0 carrier:0 + collisions:0 txqueuelen:100 + Interrupt:9 Base address:0x1400 5. Switch Configuration ======================= - For this section, "switch" refers to whatever system the +For this section, "switch" refers to whatever system the bonded devices are directly connected to (i.e., where the other end of the cable plugs into). This may be an actual dedicated switch device, or it may be another regular system (e.g., another computer running Linux), - The active-backup, balance-tlb and balance-alb modes do not +The active-backup, balance-tlb and balance-alb modes do not require any specific configuration of the switch. - The 802.3ad mode requires that the switch have the appropriate +The 802.3ad mode requires that the switch have the appropriate ports configured as an 802.3ad aggregation. The precise method used to configure this varies from switch to switch, but, for example, a Cisco 3550 series switch requires that the appropriate ports first be @@ -1804,7 +1839,7 @@ grouped together in a single etherchannel instance, then that etherchannel is set to mode "lacp" to enable 802.3ad (instead of standard EtherChannel). - The balance-rr, balance-xor and broadcast modes generally +The balance-rr, balance-xor and broadcast modes generally require that the switch have the appropriate ports grouped together. The nomenclature for such a group differs between switches, it may be called an "etherchannel" (as in the Cisco example, above), a "trunk @@ -1820,7 +1855,7 @@ with another EtherChannel group. 6. 802.1q VLAN Support ====================== - It is possible to configure VLAN devices over a bond interface +It is possible to configure VLAN devices over a bond interface using the 8021q driver. However, only packets coming from the 8021q driver and passing through bonding will be tagged by default. Self generated packets, for example, bonding's learning packets or ARP @@ -1829,7 +1864,7 @@ tagged internally by bonding itself. As a result, bonding must "learn" the VLAN IDs configured above it, and use those IDs to tag self generated packets. - For reasons of simplicity, and to support the use of adapters +For reasons of simplicity, and to support the use of adapters that can do VLAN hardware acceleration offloading, the bonding interface declares itself as fully hardware offloading capable, it gets the add_vid/kill_vid notifications to gather the necessary @@ -1839,7 +1874,7 @@ should go through an adapter that is not offloading capable are "un-accelerated" by the bonding driver so the VLAN tag sits in the regular location. - VLAN interfaces *must* be added on top of a bonding interface +VLAN interfaces *must* be added on top of a bonding interface only after enslaving at least one slave. The bonding interface has a hardware address of 00:00:00:00:00:00 until the first slave is added. If the VLAN interface is created prior to the first enslavement, it @@ -1847,23 +1882,23 @@ would pick up the all-zeroes hardware address. Once the first slave is attached to the bond, the bond device itself will pick up the slave's hardware address, which is then available for the VLAN device. - Also, be aware that a similar problem can occur if all slaves +Also, be aware that a similar problem can occur if all slaves are released from a bond that still has one or more VLAN interfaces on top of it. When a new slave is added, the bonding interface will obtain its hardware address from the first slave, which might not match the hardware address of the VLAN interfaces (which was ultimately copied from an earlier slave). - There are two methods to insure that the VLAN device operates +There are two methods to insure that the VLAN device operates with the correct hardware address if all slaves are removed from a bond interface: - 1. Remove all VLAN interfaces then recreate them +1. Remove all VLAN interfaces then recreate them - 2. Set the bonding interface's hardware address so that it +2. Set the bonding interface's hardware address so that it matches the hardware address of the VLAN interfaces. - Note that changing a VLAN interface's HW address would set the +Note that changing a VLAN interface's HW address would set the underlying device -- i.e. the bonding interface -- to promiscuous mode, which might not be what you want. @@ -1871,24 +1906,24 @@ mode, which might not be what you want. 7. Link Monitoring ================== - The bonding driver at present supports two schemes for +The bonding driver at present supports two schemes for monitoring a slave device's link state: the ARP monitor and the MII monitor. - At the present time, due to implementation restrictions in the +At the present time, due to implementation restrictions in the bonding driver itself, it is not possible to enable both ARP and MII monitoring simultaneously. 7.1 ARP Monitor Operation ------------------------- - The ARP monitor operates as its name suggests: it sends ARP +The ARP monitor operates as its name suggests: it sends ARP queries to one or more designated peer systems on the network, and uses the response as an indication that the link is operating. This gives some assurance that traffic is actually flowing to and from one or more peers on the local network. - The ARP monitor relies on the device driver itself to verify +The ARP monitor relies on the device driver itself to verify that traffic is flowing. In particular, the driver must keep up to date the last receive time, dev->last_rx. Drivers that use NETIF_F_LLTX flag must also update netdev_queue->trans_start. If they do not, then the @@ -1900,36 +1935,36 @@ your device driver is not updating last_rx and trans_start. 7.2 Configuring Multiple ARP Targets ------------------------------------ - While ARP monitoring can be done with just one target, it can +While ARP monitoring can be done with just one target, it can be useful in a High Availability setup to have several targets to monitor. In the case of just one target, the target itself may go down or have a problem making it unresponsive to ARP requests. Having an additional target (or several) increases the reliability of the ARP monitoring. - Multiple ARP targets must be separated by commas as follows: +Multiple ARP targets must be separated by commas as follows:: -# example options for ARP monitoring with three targets -alias bond0 bonding -options bond0 arp_interval=60 arp_ip_target=192.168.0.1,192.168.0.3,192.168.0.9 + # example options for ARP monitoring with three targets + alias bond0 bonding + options bond0 arp_interval=60 arp_ip_target=192.168.0.1,192.168.0.3,192.168.0.9 - For just a single target the options would resemble: +For just a single target the options would resemble:: -# example options for ARP monitoring with one target -alias bond0 bonding -options bond0 arp_interval=60 arp_ip_target=192.168.0.100 + # example options for ARP monitoring with one target + alias bond0 bonding + options bond0 arp_interval=60 arp_ip_target=192.168.0.100 7.3 MII Monitor Operation ------------------------- - The MII monitor monitors only the carrier state of the local +The MII monitor monitors only the carrier state of the local network interface. It accomplishes this in one of three ways: by depending upon the device driver to maintain its carrier state, by querying the device's MII registers, or by making an ethtool query to the device. - If the use_carrier module parameter is 1 (the default value), +If the use_carrier module parameter is 1 (the default value), then the MII monitor will rely on the driver for carrier state information (via the netif_carrier subsystem). As explained in the use_carrier parameter information, above, if the MII monitor fails to @@ -1937,7 +1972,7 @@ detect carrier loss on the device (e.g., when the cable is physically disconnected), it may be that the driver does not support netif_carrier. - If use_carrier is 0, then the MII monitor will first query the +If use_carrier is 0, then the MII monitor will first query the device's (via ioctl) MII registers and check the link state. If that request fails (not just that it returns carrier down), then the MII monitor will make an ethtool ETHOOL_GLINK request to attempt to obtain @@ -1952,25 +1987,25 @@ up. 8.1 Adventures in Routing ------------------------- - When bonding is configured, it is important that the slave +When bonding is configured, it is important that the slave devices not have routes that supersede routes of the master (or, generally, not have routes at all). For example, suppose the bonding device bond0 has two slaves, eth0 and eth1, and the routing table is -as follows: +as follows:: -Kernel IP routing table -Destination Gateway Genmask Flags MSS Window irtt Iface -10.0.0.0 0.0.0.0 255.255.0.0 U 40 0 0 eth0 -10.0.0.0 0.0.0.0 255.255.0.0 U 40 0 0 eth1 -10.0.0.0 0.0.0.0 255.255.0.0 U 40 0 0 bond0 -127.0.0.0 0.0.0.0 255.0.0.0 U 40 0 0 lo + Kernel IP routing table + Destination Gateway Genmask Flags MSS Window irtt Iface + 10.0.0.0 0.0.0.0 255.255.0.0 U 40 0 0 eth0 + 10.0.0.0 0.0.0.0 255.255.0.0 U 40 0 0 eth1 + 10.0.0.0 0.0.0.0 255.255.0.0 U 40 0 0 bond0 + 127.0.0.0 0.0.0.0 255.0.0.0 U 40 0 0 lo - This routing configuration will likely still update the +This routing configuration will likely still update the receive/transmit times in the driver (needed by the ARP monitor), but may bypass the bonding driver (because outgoing traffic to, in this case, another host on network 10 would use eth0 or eth1 before bond0). - The ARP monitor (and ARP itself) may become confused by this +The ARP monitor (and ARP itself) may become confused by this configuration, because ARP requests (generated by the ARP monitor) will be sent on one interface (bond0), but the corresponding reply will arrive on a different interface (eth0). This reply looks to ARP @@ -1978,7 +2013,7 @@ as an unsolicited ARP reply (because ARP matches replies on an interface basis), and is discarded. The MII monitor is not affected by the state of the routing table. - The solution here is simply to insure that slaves do not have +The solution here is simply to insure that slaves do not have routes of their own, and if for some reason they must, those routes do not supersede routes of their master. This should generally be the case, but unusual configurations or errant manual or automatic static @@ -1987,22 +2022,22 @@ route additions may cause trouble. 8.2 Ethernet Device Renaming ---------------------------- - On systems with network configuration scripts that do not +On systems with network configuration scripts that do not associate physical devices directly with network interface names (so that the same physical device always has the same "ethX" name), it may be necessary to add some special logic to config files in /etc/modprobe.d/. - For example, given a modules.conf containing the following: +For example, given a modules.conf containing the following:: -alias bond0 bonding -options bond0 mode=some-mode miimon=50 -alias eth0 tg3 -alias eth1 tg3 -alias eth2 e1000 -alias eth3 e1000 + alias bond0 bonding + options bond0 mode=some-mode miimon=50 + alias eth0 tg3 + alias eth1 tg3 + alias eth2 e1000 + alias eth3 e1000 - If neither eth0 and eth1 are slaves to bond0, then when the +If neither eth0 and eth1 are slaves to bond0, then when the bond0 interface comes up, the devices may end up reordered. This happens because bonding is loaded first, then its slave device's drivers are loaded next. Since no other drivers have been loaded, @@ -2010,36 +2045,36 @@ when the e1000 driver loads, it will receive eth0 and eth1 for its devices, but the bonding configuration tries to enslave eth2 and eth3 (which may later be assigned to the tg3 devices). - Adding the following: +Adding the following:: -add above bonding e1000 tg3 + add above bonding e1000 tg3 - causes modprobe to load e1000 then tg3, in that order, when +causes modprobe to load e1000 then tg3, in that order, when bonding is loaded. This command is fully documented in the modules.conf manual page. - On systems utilizing modprobe an equivalent problem can occur. +On systems utilizing modprobe an equivalent problem can occur. In this case, the following can be added to config files in -/etc/modprobe.d/ as: +/etc/modprobe.d/ as:: -softdep bonding pre: tg3 e1000 + softdep bonding pre: tg3 e1000 - This will load tg3 and e1000 modules before loading the bonding one. +This will load tg3 and e1000 modules before loading the bonding one. Full documentation on this can be found in the modprobe.d and modprobe manual pages. 8.3. Painfully Slow Or No Failed Link Detection By Miimon --------------------------------------------------------- - By default, bonding enables the use_carrier option, which +By default, bonding enables the use_carrier option, which instructs bonding to trust the driver to maintain carrier state. - As discussed in the options section, above, some drivers do +As discussed in the options section, above, some drivers do not support the netif_carrier_on/_off link state tracking system. With use_carrier enabled, bonding will always see these links as up, regardless of their actual state. - Additionally, other drivers do support netif_carrier, but do +Additionally, other drivers do support netif_carrier, but do not maintain it in real time, e.g., only polling the link state at some fixed interval. In this case, miimon will detect failures, but only after some long period of time has expired. If it appears that @@ -2051,7 +2086,7 @@ use_carrier=0 method of querying the registers directly works). If use_carrier=0 does not improve the failover, then the driver may cache the registers, or the problem may be elsewhere. - Also, remember that miimon only checks for the device's +Also, remember that miimon only checks for the device's carrier state. It has no way to determine the state of devices on or beyond other ports of a switch, or if a switch is refusing to pass traffic while still maintaining carrier on. @@ -2059,7 +2094,7 @@ traffic while still maintaining carrier on. 9. SNMP agents =============== - If running SNMP agents, the bonding driver should be loaded +If running SNMP agents, the bonding driver should be loaded before any network drivers participating in a bond. This requirement is due to the interface index (ipAdEntIfIndex) being associated to the first interface found with a given IP address. That is, there is @@ -2070,6 +2105,8 @@ with the eth0 interface. This configuration is shown below, the IP address 192.168.1.1 has an interface index of 2 which indexes to eth0 in the ifDescr table (ifDescr.2). +:: + interfaces.ifTable.ifEntry.ifDescr.1 = lo interfaces.ifTable.ifEntry.ifDescr.2 = eth0 interfaces.ifTable.ifEntry.ifDescr.3 = eth1 @@ -2081,7 +2118,7 @@ in the ifDescr table (ifDescr.2). ip.ipAddrTable.ipAddrEntry.ipAdEntIfIndex.10.74.20.94 = 4 ip.ipAddrTable.ipAddrEntry.ipAdEntIfIndex.127.0.0.1 = 1 - This problem is avoided by loading the bonding driver before +This problem is avoided by loading the bonding driver before any network drivers participating in a bond. Below is an example of loading the bonding driver first, the IP address 192.168.1.1 is correctly associated with ifDescr.2. @@ -2097,7 +2134,7 @@ correctly associated with ifDescr.2. ip.ipAddrTable.ipAddrEntry.ipAdEntIfIndex.10.74.20.94 = 5 ip.ipAddrTable.ipAddrEntry.ipAdEntIfIndex.127.0.0.1 = 1 - While some distributions may not report the interface name in +While some distributions may not report the interface name in ifDescr, the association between the IP address and IfIndex remains and SNMP functions such as Interface_Scan_Next will report that association. @@ -2105,34 +2142,34 @@ association. 10. Promiscuous mode ==================== - When running network monitoring tools, e.g., tcpdump, it is +When running network monitoring tools, e.g., tcpdump, it is common to enable promiscuous mode on the device, so that all traffic is seen (instead of seeing only traffic destined for the local host). The bonding driver handles promiscuous mode changes to the bonding master device (e.g., bond0), and propagates the setting to the slave devices. - For the balance-rr, balance-xor, broadcast, and 802.3ad modes, +For the balance-rr, balance-xor, broadcast, and 802.3ad modes, the promiscuous mode setting is propagated to all slaves. - For the active-backup, balance-tlb and balance-alb modes, the +For the active-backup, balance-tlb and balance-alb modes, the promiscuous mode setting is propagated only to the active slave. - For balance-tlb mode, the active slave is the slave currently +For balance-tlb mode, the active slave is the slave currently receiving inbound traffic. - For balance-alb mode, the active slave is the slave used as a +For balance-alb mode, the active slave is the slave used as a "primary." This slave is used for mode-specific control traffic, for sending to peers that are unassigned or if the load is unbalanced. - For the active-backup, balance-tlb and balance-alb modes, when +For the active-backup, balance-tlb and balance-alb modes, when the active slave changes (e.g., due to a link failure), the promiscuous setting will be propagated to the new active slave. 11. Configuring Bonding for High Availability ============================================= - High Availability refers to configurations that provide +High Availability refers to configurations that provide maximum network availability by having redundant or backup devices, links or switches between the host and the rest of the world. The goal is to provide the maximum availability of network connectivity @@ -2142,7 +2179,7 @@ could provide higher throughput. 11.1 High Availability in a Single Switch Topology -------------------------------------------------- - If two hosts (or a host and a single switch) are directly +If two hosts (or a host and a single switch) are directly connected via multiple physical links, then there is no availability penalty to optimizing for maximum bandwidth. In this case, there is only one switch (or peer), so if it fails, there is no alternative @@ -2150,32 +2187,32 @@ access to fail over to. Additionally, the bonding load balance modes support link monitoring of their members, so if individual links fail, the load will be rebalanced across the remaining devices. - See Section 12, "Configuring Bonding for Maximum Throughput" +See Section 12, "Configuring Bonding for Maximum Throughput" for information on configuring bonding with one peer device. 11.2 High Availability in a Multiple Switch Topology ---------------------------------------------------- - With multiple switches, the configuration of bonding and the +With multiple switches, the configuration of bonding and the network changes dramatically. In multiple switch topologies, there is a trade off between network availability and usable bandwidth. - Below is a sample network, configured to maximize the -availability of the network: - - | | - |port3 port3| - +-----+----+ +-----+----+ - | |port2 ISL port2| | - | switch A +--------------------------+ switch B | - | | | | - +-----+----+ +-----++---+ - |port1 port1| - | +-------+ | - +-------------+ host1 +---------------+ - eth0 +-------+ eth1 - - In this configuration, there is a link between the two +Below is a sample network, configured to maximize the +availability of the network:: + + | | + |port3 port3| + +-----+----+ +-----+----+ + | |port2 ISL port2| | + | switch A +--------------------------+ switch B | + | | | | + +-----+----+ +-----++---+ + |port1 port1| + | +-------+ | + +-------------+ host1 +---------------+ + eth0 +-------+ eth1 + +In this configuration, there is a link between the two switches (ISL, or inter switch link), and multiple ports connecting to the outside world ("port3" on each switch). There is no technical reason that this could not be extended to a third switch. @@ -2183,19 +2220,21 @@ reason that this could not be extended to a third switch. 11.2.1 HA Bonding Mode Selection for Multiple Switch Topology ------------------------------------------------------------- - In a topology such as the example above, the active-backup and +In a topology such as the example above, the active-backup and broadcast modes are the only useful bonding modes when optimizing for availability; the other modes require all links to terminate on the same peer for them to behave rationally. -active-backup: This is generally the preferred mode, particularly if +active-backup: + This is generally the preferred mode, particularly if the switches have an ISL and play together well. If the network configuration is such that one switch is specifically a backup switch (e.g., has lower capacity, higher cost, etc), then the primary option can be used to insure that the preferred link is always used when it is available. -broadcast: This mode is really a special purpose mode, and is suitable +broadcast: + This mode is really a special purpose mode, and is suitable only for very specific needs. For example, if the two switches are not connected (no ISL), and the networks beyond them are totally independent. In this case, if it is @@ -2205,7 +2244,7 @@ broadcast: This mode is really a special purpose mode, and is suitable 11.2.2 HA Link Monitoring Selection for Multiple Switch Topology ---------------------------------------------------------------- - The choice of link monitoring ultimately depends upon your +The choice of link monitoring ultimately depends upon your switch. If the switch can reliably fail ports in response to other failures, then either the MII or ARP monitors should work. For example, in the above example, if the "port3" link fails at the remote @@ -2213,7 +2252,7 @@ end, the MII monitor has no direct means to detect this. The ARP monitor could be configured with a target at the remote end of port3, thus detecting that failure without switch support. - In general, however, in a multiple switch topology, the ARP +In general, however, in a multiple switch topology, the ARP monitor can provide a higher level of reliability in detecting end to end connectivity failures (which may be caused by the failure of any individual component to pass traffic for any reason). Additionally, @@ -2222,7 +2261,7 @@ one for each switch in the network). This will insure that, regardless of which switch is active, the ARP monitor has a suitable target to query. - Note, also, that of late many switches now support a functionality +Note, also, that of late many switches now support a functionality generally referred to as "trunk failover." This is a feature of the switch that causes the link state of a particular switch port to be set down (or up) when the state of another switch port goes down (or up). @@ -2238,18 +2277,18 @@ suitable switches. 12.1 Maximizing Throughput in a Single Switch Topology ------------------------------------------------------ - In a single switch configuration, the best method to maximize +In a single switch configuration, the best method to maximize throughput depends upon the application and network environment. The various load balancing modes each have strengths and weaknesses in different environments, as detailed below. - For this discussion, we will break down the topologies into +For this discussion, we will break down the topologies into two categories. Depending upon the destination of most traffic, we categorize them into either "gatewayed" or "local" configurations. - In a gatewayed configuration, the "switch" is acting primarily +In a gatewayed configuration, the "switch" is acting primarily as a router, and the majority of traffic passes through this router to -other networks. An example would be the following: +other networks. An example would be the following:: +----------+ +----------+ @@ -2259,25 +2298,25 @@ other networks. An example would be the following: | |eth1 port2| | here somewhere +----------+ +----------+ - The router may be a dedicated router device, or another host +The router may be a dedicated router device, or another host acting as a gateway. For our discussion, the important point is that the majority of traffic from Host A will pass through the router to some other network before reaching its final destination. - In a gatewayed network configuration, although Host A may +In a gatewayed network configuration, although Host A may communicate with many other systems, all of its traffic will be sent and received via one other peer on the local network, the router. - Note that the case of two systems connected directly via +Note that the case of two systems connected directly via multiple physical links is, for purposes of configuring bonding, the same as a gatewayed configuration. In that case, it happens that all traffic is destined for the "gateway" itself, not some other network beyond the gateway. - In a local configuration, the "switch" is acting primarily as +In a local configuration, the "switch" is acting primarily as a switch, and the majority of traffic passes through this switch to reach other stations on the same network. An example would be the -following: +following:: +----------+ +----------+ +--------+ | |eth0 port1| +-------+ Host B | @@ -2287,19 +2326,19 @@ following: +----------+ +----------+port4 +--------+ - Again, the switch may be a dedicated switch device, or another +Again, the switch may be a dedicated switch device, or another host acting as a gateway. For our discussion, the important point is that the majority of traffic from Host A is destined for other hosts on the same local network (Hosts B and C in the above example). - In summary, in a gatewayed configuration, traffic to and from +In summary, in a gatewayed configuration, traffic to and from the bonded device will be to the same MAC level peer on the network (the gateway itself, i.e., the router), regardless of its final destination. In a local configuration, traffic flows directly to and from the final destinations, thus, each destination (Host B, Host C) will be addressed directly by their individual MAC addresses. - This distinction between a gatewayed and a local network +This distinction between a gatewayed and a local network configuration is important because many of the load balancing modes available use the MAC addresses of the local network source and destination to make load balancing decisions. The behavior of each @@ -2309,11 +2348,12 @@ mode is described below. 12.1.1 MT Bonding Mode Selection for Single Switch Topology ----------------------------------------------------------- - This configuration is the easiest to set up and to understand, +This configuration is the easiest to set up and to understand, although you will have to decide which bonding mode best suits your needs. The trade offs for each mode are detailed below: -balance-rr: This mode is the only mode that will permit a single +balance-rr: + This mode is the only mode that will permit a single TCP/IP connection to stripe traffic across multiple interfaces. It is therefore the only mode that will allow a single TCP/IP stream to utilize more than one interface's @@ -2351,7 +2391,8 @@ balance-rr: This mode is the only mode that will permit a single This mode requires the switch to have the appropriate ports configured for "etherchannel" or "trunking." -active-backup: There is not much advantage in this network topology to +active-backup: + There is not much advantage in this network topology to the active-backup mode, as the inactive backup devices are all connected to the same peer as the primary. In this case, a load balancing mode (with link monitoring) will provide the @@ -2361,7 +2402,8 @@ active-backup: There is not much advantage in this network topology to have value if the hardware available does not support any of the load balance modes. -balance-xor: This mode will limit traffic such that packets destined +balance-xor: + This mode will limit traffic such that packets destined for specific peers will always be sent over the same interface. Since the destination is determined by the MAC addresses involved, this mode works best in a "local" network @@ -2373,10 +2415,12 @@ balance-xor: This mode will limit traffic such that packets destined As with balance-rr, the switch ports need to be configured for "etherchannel" or "trunking." -broadcast: Like active-backup, there is not much advantage to this +broadcast: + Like active-backup, there is not much advantage to this mode in this type of network topology. -802.3ad: This mode can be a good choice for this type of network +802.3ad: + This mode can be a good choice for this type of network topology. The 802.3ad mode is an IEEE standard, so all peers that implement 802.3ad should interoperate well. The 802.3ad protocol includes automatic configuration of the aggregates, @@ -2390,7 +2434,7 @@ broadcast: Like active-backup, there is not much advantage to this the same speed and duplex. Also, as with all bonding load balance modes other than balance-rr, no single connection will be able to utilize more than a single interface's worth of - bandwidth. + bandwidth. Additionally, the linux bonding 802.3ad implementation distributes traffic by peer (using an XOR of MAC addresses @@ -2404,7 +2448,8 @@ broadcast: Like active-backup, there is not much advantage to this Finally, the 802.3ad mode mandates the use of the MII monitor, therefore, the ARP monitor is not available in this mode. -balance-tlb: The balance-tlb mode balances outgoing traffic by peer. +balance-tlb: + The balance-tlb mode balances outgoing traffic by peer. Since the balancing is done according to MAC address, in a "gatewayed" configuration (as described above), this mode will send all traffic across a single device. However, in a @@ -2422,7 +2467,8 @@ balance-tlb: The balance-tlb mode balances outgoing traffic by peer. network device driver of the slave interfaces, and the ARP monitor is not available. -balance-alb: This mode is everything that balance-tlb is, and more. +balance-alb: + This mode is everything that balance-tlb is, and more. It has all of the features (and restrictions) of balance-tlb, and will also balance incoming traffic from local network peers (as described in the Bonding Module Options section, @@ -2435,7 +2481,7 @@ balance-alb: This mode is everything that balance-tlb is, and more. 12.1.2 MT Link Monitoring for Single Switch Topology ---------------------------------------------------- - The choice of link monitoring may largely depend upon which +The choice of link monitoring may largely depend upon which mode you choose to use. The more advanced load balancing modes do not support the use of the ARP monitor, and are thus restricted to using the MII monitor (which does not provide as high a level of end to end @@ -2444,27 +2490,27 @@ assurance as the ARP monitor). 12.2 Maximum Throughput in a Multiple Switch Topology ----------------------------------------------------- - Multiple switches may be utilized to optimize for throughput +Multiple switches may be utilized to optimize for throughput when they are configured in parallel as part of an isolated network -between two or more systems, for example: - - +-----------+ - | Host A | - +-+---+---+-+ - | | | - +--------+ | +---------+ - | | | - +------+---+ +-----+----+ +-----+----+ - | Switch A | | Switch B | | Switch C | - +------+---+ +-----+----+ +-----+----+ - | | | - +--------+ | +---------+ - | | | - +-+---+---+-+ - | Host B | - +-----------+ - - In this configuration, the switches are isolated from one +between two or more systems, for example:: + + +-----------+ + | Host A | + +-+---+---+-+ + | | | + +--------+ | +---------+ + | | | + +------+---+ +-----+----+ +-----+----+ + | Switch A | | Switch B | | Switch C | + +------+---+ +-----+----+ +-----+----+ + | | | + +--------+ | +---------+ + | | | + +-+---+---+-+ + | Host B | + +-----------+ + +In this configuration, the switches are isolated from one another. One reason to employ a topology such as this is for an isolated network with many hosts (a cluster configured for high performance, for example), using multiple smaller switches can be more @@ -2472,14 +2518,14 @@ cost effective than a single larger switch, e.g., on a network with 24 hosts, three 24 port switches can be significantly less expensive than a single 72 port switch. - If access beyond the network is required, an individual host +If access beyond the network is required, an individual host can be equipped with an additional network device connected to an external network; this host then additionally acts as a gateway. 12.2.1 MT Bonding Mode Selection for Multiple Switch Topology ------------------------------------------------------------- - In actual practice, the bonding mode typically employed in +In actual practice, the bonding mode typically employed in configurations of this type is balance-rr. Historically, in this network configuration, the usual caveats about out of order packet delivery are mitigated by the use of network adapters that do not do @@ -2492,7 +2538,7 @@ utilize greater than one interface's bandwidth. 12.2.2 MT Link Monitoring for Multiple Switch Topology ------------------------------------------------------ - Again, in actual practice, the MII monitor is most often used +Again, in actual practice, the MII monitor is most often used in this configuration, as performance is given preference over availability. The ARP monitor will function in this topology, but its advantages over the MII monitor are mitigated by the volume of probes @@ -2505,10 +2551,10 @@ host in the network is configured with bonding). 13.1 Link Establishment and Failover Delays ------------------------------------------- - Some switches exhibit undesirable behavior with regard to the +Some switches exhibit undesirable behavior with regard to the timing of link up and down reporting by the switch. - First, when a link comes up, some switches may indicate that +First, when a link comes up, some switches may indicate that the link is up (carrier available), but not pass traffic over the interface for some period of time. This delay is typically due to some type of autonegotiation or routing protocol, but may also occur @@ -2517,12 +2563,12 @@ failure). If you find this to be a problem, specify an appropriate value to the updelay bonding module option to delay the use of the relevant interface(s). - Second, some switches may "bounce" the link state one or more +Second, some switches may "bounce" the link state one or more times while a link is changing state. This occurs most commonly while the switch is initializing. Again, an appropriate updelay value may help. - Note that when a bonding interface has no active links, the +Note that when a bonding interface has no active links, the driver will immediately reuse the first link that goes up, even if the updelay parameter has been specified (the updelay is ignored in this case). If there are slave interfaces waiting for the updelay timeout @@ -2532,7 +2578,7 @@ value of updelay has been overestimated, and since this occurs only in cases with no connectivity, there is no additional penalty for ignoring the updelay. - In addition to the concerns about switch timings, if your +In addition to the concerns about switch timings, if your switches take a long time to go into backup mode, it may be desirable to not activate a backup interface immediately after a link goes down. Failover may be delayed via the downdelay bonding module option. @@ -2540,31 +2586,31 @@ Failover may be delayed via the downdelay bonding module option. 13.2 Duplicated Incoming Packets -------------------------------- - NOTE: Starting with version 3.0.2, the bonding driver has logic to +NOTE: Starting with version 3.0.2, the bonding driver has logic to suppress duplicate packets, which should largely eliminate this problem. The following description is kept for reference. - It is not uncommon to observe a short burst of duplicated +It is not uncommon to observe a short burst of duplicated traffic when the bonding device is first used, or after it has been idle for some period of time. This is most easily observed by issuing a "ping" to some other host on the network, and noticing that the output from ping flags duplicates (typically one per slave). - For example, on a bond in active-backup mode with five slaves -all connected to one switch, the output may appear as follows: - -# ping -n 10.0.4.2 -PING 10.0.4.2 (10.0.4.2) from 10.0.3.10 : 56(84) bytes of data. -64 bytes from 10.0.4.2: icmp_seq=1 ttl=64 time=13.7 ms -64 bytes from 10.0.4.2: icmp_seq=1 ttl=64 time=13.8 ms (DUP!) -64 bytes from 10.0.4.2: icmp_seq=1 ttl=64 time=13.8 ms (DUP!) -64 bytes from 10.0.4.2: icmp_seq=1 ttl=64 time=13.8 ms (DUP!) -64 bytes from 10.0.4.2: icmp_seq=1 ttl=64 time=13.8 ms (DUP!) -64 bytes from 10.0.4.2: icmp_seq=2 ttl=64 time=0.216 ms -64 bytes from 10.0.4.2: icmp_seq=3 ttl=64 time=0.267 ms -64 bytes from 10.0.4.2: icmp_seq=4 ttl=64 time=0.222 ms - - This is not due to an error in the bonding driver, rather, it +For example, on a bond in active-backup mode with five slaves +all connected to one switch, the output may appear as follows:: + + # ping -n 10.0.4.2 + PING 10.0.4.2 (10.0.4.2) from 10.0.3.10 : 56(84) bytes of data. + 64 bytes from 10.0.4.2: icmp_seq=1 ttl=64 time=13.7 ms + 64 bytes from 10.0.4.2: icmp_seq=1 ttl=64 time=13.8 ms (DUP!) + 64 bytes from 10.0.4.2: icmp_seq=1 ttl=64 time=13.8 ms (DUP!) + 64 bytes from 10.0.4.2: icmp_seq=1 ttl=64 time=13.8 ms (DUP!) + 64 bytes from 10.0.4.2: icmp_seq=1 ttl=64 time=13.8 ms (DUP!) + 64 bytes from 10.0.4.2: icmp_seq=2 ttl=64 time=0.216 ms + 64 bytes from 10.0.4.2: icmp_seq=3 ttl=64 time=0.267 ms + 64 bytes from 10.0.4.2: icmp_seq=4 ttl=64 time=0.222 ms + +This is not due to an error in the bonding driver, rather, it is a side effect of how many switches update their MAC forwarding tables. Initially, the switch does not associate the MAC address in the packet with a particular switch port, and so it may send the @@ -2574,7 +2620,7 @@ single switch, when the switch (temporarily) floods the traffic to all ports, the bond device receives multiple copies of the same packet (one per slave device). - The duplicated packet behavior is switch dependent, some +The duplicated packet behavior is switch dependent, some switches exhibit this, and some do not. On switches that display this behavior, it can be induced by clearing the MAC forwarding table (on most Cisco switches, the privileged command "clear mac address-table @@ -2583,16 +2629,16 @@ dynamic" will accomplish this). 14. Hardware Specific Considerations ==================================== - This section contains additional information for configuring +This section contains additional information for configuring bonding on specific hardware platforms, or for interfacing bonding with particular switches or other devices. 14.1 IBM BladeCenter -------------------- - This applies to the JS20 and similar systems. +This applies to the JS20 and similar systems. - On the JS20 blades, the bonding driver supports only +On the JS20 blades, the bonding driver supports only balance-rr, active-backup, balance-tlb and balance-alb modes. This is largely due to the network topology inside the BladeCenter, detailed below. @@ -2600,7 +2646,7 @@ below. JS20 network adapter information -------------------------------- - All JS20s come with two Broadcom Gigabit Ethernet ports +All JS20s come with two Broadcom Gigabit Ethernet ports integrated on the planar (that's "motherboard" in IBM-speak). In the BladeCenter chassis, the eth0 port of all JS20 blades is hard wired to I/O Module #1; similarly, all eth1 ports are wired to I/O Module #2. @@ -2608,36 +2654,36 @@ An add-on Broadcom daughter card can be installed on a JS20 to provide two more Gigabit Ethernet ports. These ports, eth2 and eth3, are wired to I/O Modules 3 and 4, respectively. - Each I/O Module may contain either a switch or a passthrough +Each I/O Module may contain either a switch or a passthrough module (which allows ports to be directly connected to an external switch). Some bonding modes require a specific BladeCenter internal network topology in order to function; these are detailed below. - Additional BladeCenter-specific networking information can be +Additional BladeCenter-specific networking information can be found in two IBM Redbooks (www.ibm.com/redbooks): -"IBM eServer BladeCenter Networking Options" -"IBM eServer BladeCenter Layer 2-7 Network Switching" +- "IBM eServer BladeCenter Networking Options" +- "IBM eServer BladeCenter Layer 2-7 Network Switching" BladeCenter networking configuration ------------------------------------ - Because a BladeCenter can be configured in a very large number +Because a BladeCenter can be configured in a very large number of ways, this discussion will be confined to describing basic configurations. - Normally, Ethernet Switch Modules (ESMs) are used in I/O +Normally, Ethernet Switch Modules (ESMs) are used in I/O modules 1 and 2. In this configuration, the eth0 and eth1 ports of a JS20 will be connected to different internal switches (in the respective I/O modules). - A passthrough module (OPM or CPM, optical or copper, +A passthrough module (OPM or CPM, optical or copper, passthrough module) connects the I/O module directly to an external switch. By using PMs in I/O module #1 and #2, the eth0 and eth1 interfaces of a JS20 can be redirected to the outside world and connected to a common external switch. - Depending upon the mix of ESMs and PMs, the network will +Depending upon the mix of ESMs and PMs, the network will appear to bonding as either a single switch topology (all PMs) or as a multiple switch topology (one or more ESMs, zero or more PMs). It is also possible to connect ESMs together, resulting in a configuration @@ -2647,24 +2693,24 @@ Topology," above. Requirements for specific modes ------------------------------- - The balance-rr mode requires the use of passthrough modules +The balance-rr mode requires the use of passthrough modules for devices in the bond, all connected to an common external switch. That switch must be configured for "etherchannel" or "trunking" on the appropriate ports, as is usual for balance-rr. - The balance-alb and balance-tlb modes will function with +The balance-alb and balance-tlb modes will function with either switch modules or passthrough modules (or a mix). The only specific requirement for these modes is that all network interfaces must be able to reach all destinations for traffic sent over the bonding device (i.e., the network must converge at some point outside the BladeCenter). - The active-backup mode has no additional requirements. +The active-backup mode has no additional requirements. Link monitoring issues ---------------------- - When an Ethernet Switch Module is in place, only the ARP +When an Ethernet Switch Module is in place, only the ARP monitor will reliably detect link loss to an external switch. This is nothing unusual, but examination of the BladeCenter cabinet would suggest that the "external" network ports are the ethernet ports for @@ -2672,166 +2718,173 @@ the system, when it fact there is a switch between these "external" ports and the devices on the JS20 system itself. The MII monitor is only able to detect link failures between the ESM and the JS20 system. - When a passthrough module is in place, the MII monitor does +When a passthrough module is in place, the MII monitor does detect failures to the "external" port, which is then directly connected to the JS20 system. Other concerns -------------- - The Serial Over LAN (SoL) link is established over the primary +The Serial Over LAN (SoL) link is established over the primary ethernet (eth0) only, therefore, any loss of link to eth0 will result in losing your SoL connection. It will not fail over with other network traffic, as the SoL system is beyond the control of the bonding driver. - It may be desirable to disable spanning tree on the switch +It may be desirable to disable spanning tree on the switch (either the internal Ethernet Switch Module, or an external switch) to avoid fail-over delay issues when using bonding. - + 15. Frequently Asked Questions ============================== 1. Is it SMP safe? +------------------- - Yes. The old 2.0.xx channel bonding patch was not SMP safe. +Yes. The old 2.0.xx channel bonding patch was not SMP safe. The new driver was designed to be SMP safe from the start. 2. What type of cards will work with it? +----------------------------------------- - Any Ethernet type cards (you can even mix cards - a Intel +Any Ethernet type cards (you can even mix cards - a Intel EtherExpress PRO/100 and a 3com 3c905b, for example). For most modes, devices need not be of the same speed. - Starting with version 3.2.1, bonding also supports Infiniband +Starting with version 3.2.1, bonding also supports Infiniband slaves in active-backup mode. 3. How many bonding devices can I have? +---------------------------------------- - There is no limit. +There is no limit. 4. How many slaves can a bonding device have? +---------------------------------------------- - This is limited only by the number of network interfaces Linux +This is limited only by the number of network interfaces Linux supports and/or the number of network cards you can place in your system. 5. What happens when a slave link dies? +---------------------------------------- - If link monitoring is enabled, then the failing device will be +If link monitoring is enabled, then the failing device will be disabled. The active-backup mode will fail over to a backup link, and other modes will ignore the failed link. The link will continue to be monitored, and should it recover, it will rejoin the bond (in whatever manner is appropriate for the mode). See the sections on High Availability and the documentation for each mode for additional information. - - Link monitoring can be enabled via either the miimon or + +Link monitoring can be enabled via either the miimon or arp_interval parameters (described in the module parameters section, above). In general, miimon monitors the carrier state as sensed by the underlying network device, and the arp monitor (arp_interval) monitors connectivity to another host on the local network. - If no link monitoring is configured, the bonding driver will +If no link monitoring is configured, the bonding driver will be unable to detect link failures, and will assume that all links are always available. This will likely result in lost packets, and a resulting degradation of performance. The precise performance loss depends upon the bonding mode and network configuration. 6. Can bonding be used for High Availability? +---------------------------------------------- - Yes. See the section on High Availability for details. +Yes. See the section on High Availability for details. 7. Which switches/systems does it work with? +--------------------------------------------- - The full answer to this depends upon the desired mode. +The full answer to this depends upon the desired mode. - In the basic balance modes (balance-rr and balance-xor), it +In the basic balance modes (balance-rr and balance-xor), it works with any system that supports etherchannel (also called trunking). Most managed switches currently available have such support, and many unmanaged switches as well. - The advanced balance modes (balance-tlb and balance-alb) do +The advanced balance modes (balance-tlb and balance-alb) do not have special switch requirements, but do need device drivers that support specific features (described in the appropriate section under module parameters, above). - In 802.3ad mode, it works with systems that support IEEE +In 802.3ad mode, it works with systems that support IEEE 802.3ad Dynamic Link Aggregation. Most managed and many unmanaged switches currently available support 802.3ad. - The active-backup mode should work with any Layer-II switch. +The active-backup mode should work with any Layer-II switch. 8. Where does a bonding device get its MAC address from? +--------------------------------------------------------- - When using slave devices that have fixed MAC addresses, or when +When using slave devices that have fixed MAC addresses, or when the fail_over_mac option is enabled, the bonding device's MAC address is the MAC address of the active slave. - For other configurations, if not explicitly configured (with +For other configurations, if not explicitly configured (with ifconfig or ip link), the MAC address of the bonding device is taken from its first slave device. This MAC address is then passed to all following slaves and remains persistent (even if the first slave is removed) until the bonding device is brought down or reconfigured. - If you wish to change the MAC address, you can set it with -ifconfig or ip link: +If you wish to change the MAC address, you can set it with +ifconfig or ip link:: -# ifconfig bond0 hw ether 00:11:22:33:44:55 + # ifconfig bond0 hw ether 00:11:22:33:44:55 -# ip link set bond0 address 66:77:88:99:aa:bb + # ip link set bond0 address 66:77:88:99:aa:bb - The MAC address can be also changed by bringing down/up the -device and then changing its slaves (or their order): +The MAC address can be also changed by bringing down/up the +device and then changing its slaves (or their order):: -# ifconfig bond0 down ; modprobe -r bonding -# ifconfig bond0 .... up -# ifenslave bond0 eth... + # ifconfig bond0 down ; modprobe -r bonding + # ifconfig bond0 .... up + # ifenslave bond0 eth... - This method will automatically take the address from the next +This method will automatically take the address from the next slave that is added. - To restore your slaves' MAC addresses, you need to detach them -from the bond (`ifenslave -d bond0 eth0'). The bonding driver will +To restore your slaves' MAC addresses, you need to detach them +from the bond (``ifenslave -d bond0 eth0``). The bonding driver will then restore the MAC addresses that the slaves had before they were enslaved. 16. Resources and Links ======================= - The latest version of the bonding driver can be found in the latest +The latest version of the bonding driver can be found in the latest version of the linux kernel, found on http://kernel.org - The latest version of this document can be found in the latest kernel -source (named Documentation/networking/bonding.txt). +The latest version of this document can be found in the latest kernel +source (named Documentation/networking/bonding.rst). - Discussions regarding the usage of the bonding driver take place on the +Discussions regarding the usage of the bonding driver take place on the bonding-devel mailing list, hosted at sourceforge.net. If you have questions or problems, post them to the list. The list address is: bonding-devel@lists.sourceforge.net - The administrative interface (to subscribe or unsubscribe) can +The administrative interface (to subscribe or unsubscribe) can be found at: https://lists.sourceforge.net/lists/listinfo/bonding-devel - Discussions regarding the development of the bonding driver take place +Discussions regarding the development of the bonding driver take place on the main Linux network mailing list, hosted at vger.kernel.org. The list address is: netdev@vger.kernel.org - The administrative interface (to subscribe or unsubscribe) can +The administrative interface (to subscribe or unsubscribe) can be found at: http://vger.kernel.org/vger-lists.html#netdev Donald Becker's Ethernet Drivers and diag programs may be found at : - - http://web.archive.org/web/*/http://www.scyld.com/network/ + + - http://web.archive.org/web/%2E/http://www.scyld.com/network/ You will also find a lot of information regarding Ethernet, NWay, MII, etc. at www.scyld.com. - --- END -- diff --git a/Documentation/networking/device_drivers/intel/e100.rst b/Documentation/networking/device_drivers/intel/e100.rst index caf023cc88de..3ac21e7119a7 100644 --- a/Documentation/networking/device_drivers/intel/e100.rst +++ b/Documentation/networking/device_drivers/intel/e100.rst @@ -33,7 +33,7 @@ The following features are now available in supported kernels: - SNMP Channel Bonding documentation can be found in the Linux kernel source: -/Documentation/networking/bonding.txt +/Documentation/networking/bonding.rst Identifying Your Adapter diff --git a/Documentation/networking/device_drivers/intel/ixgb.rst b/Documentation/networking/device_drivers/intel/ixgb.rst index 945018207a92..ab624f1a44a8 100644 --- a/Documentation/networking/device_drivers/intel/ixgb.rst +++ b/Documentation/networking/device_drivers/intel/ixgb.rst @@ -37,7 +37,7 @@ The following features are available in this kernel: - SNMP Channel Bonding documentation can be found in the Linux kernel source: -/Documentation/networking/bonding.txt +/Documentation/networking/bonding.rst The driver information previously displayed in the /proc filesystem is not supported in this release. Alternatively, you can use ethtool (version 1.6 diff --git a/Documentation/networking/index.rst b/Documentation/networking/index.rst index fbf845fbaff7..22b872834ef0 100644 --- a/Documentation/networking/index.rst +++ b/Documentation/networking/index.rst @@ -44,6 +44,7 @@ Contents: atm ax25 baycom + bonding .. only:: subproject and html |