Table Of Contents
EtherChannel Flow-Based Limited 1:1 Redundancy
Information About EtherChannel Flow-Based Limited 1:1 Redundancy
EtherChannel Flow-Based Limited 1:1 Redundancy
How to Configure EtherChannel Flow-Based Limited 1:1 Redundancy
Configuring EtherChannel Flow-Based Limited 1:1 Redundancy with Fast-Switchover
Setting the Switchover Rate with Carrier Delay
Verifying EtherChannel Flow-Based Limited 1:1 Redundancy
Configuration Examples for EtherChannel Flow-Based Limited1:1 Redundancy
EtherChannel 1:1 Active Standby: Example
Setting Priority for 1:1 Redundancy Using LACP: Example
Feature Information for EtherChannel Flow-based Limited 1:1 Redundancy
EtherChannel Flow-Based Limited 1:1 Redundancy
First Published: June 30, 2009Last Updated: June 30, 2009EtherChannel flow-based limited 1:1 redundancy provides MAC, or layer 2, traffic protection to avoid higher layer protocols from reacting to single link failures and re-converging. To use EtherChannel flow-based limited 1:1 redundancy, you configure an EtherChannel with two ports (one active and one standby). If the active link goes down, the EtherChannel stays up and the system performs fast switchover to the hot-standby link. Depending on how you have the priorities set, when the failed link becomes operational again, the EtherChannel performs another fast switchover to revert to the original active link. if all port-priorities are the same, it will not revert, but remain on the current active link.
With 1:1 redundancy configured, only one link is active at any given time so all flows are directed over the active link.
Finding Feature Information
For the latest feature information and caveats, see the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the "Feature Information for EtherChannel Flow-based Limited 1:1 Redundancy" section.
Use Cisco Feature Navigator to find information about platform support and Cisco IOS XE software image support. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.
Contents
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Information About EtherChannel Flow-Based Limited 1:1 Redundancy
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Information About EtherChannel Flow-Based Limited 1:1 Redundancy
To configure the EtherChannel Flow-Based Limited 1:1 Redundancy feature, you should understand the following concept:
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EtherChannel Flow-Based Limited 1:1 Redundancy
EtherChannel flow-based limited 1:1 redundancy provides an EtherChannel configuration with one active link and fast switchover to a hot standby link. To use EtherChannel flow-based limited 1:1 redundancy, you configure a Link Aggregation Control Protocol (LACP) EtherChannel with two ports (one active and one standby). If the active link goes down, the EtherChannel stays up and the system performs fast switchover to the hot standby link. Depending on how the priorities of the links are set, when the failed link becomes operational again, the EtherChannel performs another fast switchover to revert to the original active link, or to the link with the higher priority.
For EtherChannel flow-based limited 1:1 redundancy to work correctly (especially the fast switchover capability) the feature must be enabled at both ends of the link.
How to Configure EtherChannel Flow-Based Limited 1:1 Redundancy
This section contains the following tasks:
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Configuring EtherChannel Flow-Based Limited 1:1 Redundancy with Fast-Switchover
To configure an LACP EtherChannel with two ports (one active and one standby), perform the following steps. This feature must be enabled at both ends of the link.
You can control which link is the primary active link by setting the port priority on the links used for the redundancy. To configure a primary link and enable the EtherChannel to revert to the original link, one link must have a higher port priority than the other and the LACP max-bundle must be set to 1. This configuration results in link 1 being active and link 2 being in hot standby state.
To prevent the switchover to revert, you can assign both links the same priority.
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DETAILED STEPS
Setting the Switchover Rate with Carrier Delay
Optionally, you can control the speed of the switchover between the active and standby links by setting the carrier delay on each link. The carrier-delay command controls how long it takes for Cisco IOS to propagate the information about the links status to other modules.
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DETAILED STEPS
Verifying EtherChannel Flow-Based Limited 1:1 Redundancy
Use these show commands to verify the configuration and to display information about the port channel.
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Configuration Examples for EtherChannel Flow-Based Limited1:1 Redundancy
This section provides the following configuration examples:
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EtherChannel 1:1 Active Standby: Example
This example shows how to configure a port channel for 1:1 link redundancy for equal priority ports so there is no preference which port is active.
Router# enableRouter# configure terminalRouter(config)# interface port-channel 2Router(config-if)# ip address 10.1.1.1 255.255.0.0Router(config-if)# negotiation autoRouter(config-if)# lacp max-bundle 1Router(config-if)# lacp fast-switchoverRouter(config)# interface Tengigabitethernet0/1/0Router(config-if)# channel-group 2 mode activeRouter(config-if)# negotiation autoRouter(config)# interface Tengigabitethernet 2/1/0Router(config-if)# channel-group 2 mode activeRouter(config-if)# negotiation autoRouter(config)# interface GigabitEthernet0/1/6Router(config-if)# negotiation autoRouter(config-if)# channel-group 19 mode activeRouter(config)# interface GigabitEthernet0/1/7Router(config-if)# negotiation autoRouter(config-if)# channel-group 19 mode activeRouter(config-if)# interface Port-channel19Router(config-if)# ip address 10.19.1.1 255.255.255.0Router(config-if)# no negotiation autoRouter(config-if)# lacp fast-switchoverRouter(config-if)# lacp max-bundle 1Router(config-if)# endNotice in the show command display the priorities are the same value.
Router# show lacp internalFlags: S - Device is requesting Slow LACPDUsF - Device is requesting Fast LACPDUsA - Device is in Active mode P - Device is in Passive modeChannel group 19LACP port Admin Oper Port PortPort Flags State Priority Key Key Number StateGi0/1/6 SA bndl 32768 0x13 0x13 0x47 0x3DGi0/1/7 FA hot-sby 32768 0x13 0x13 0x48 0x7Setting Priority for 1:1 Redundancy Using LACP: Example
This example shows how to configure an LACP EtherChannel with 1:1 redundancy. GigabitEthernet 0/1/7 is the active link, because it is configured with a lower number which give it a higher port priority.
Router# configure terminalRouter(config)# interface GigabitEthernet0/1/6Router(config-if)# lacp port-priority 32767Router(config-if)# exitRouter(config)# interface GigabitEthernet0/1/7Router(config-if)# lacp fast-switchoverRouter(config-if)# lacp max-bundle 1Router(config-if)# negotiation autoRouter(config-if)# channel-group 19 mode activeIn this show display, notice that the bundled link is set at a higher priority. This will ensure that the bundled link is used as the first active link in the standby configuration.
Router# show lacp internalFlags: S - Device is requesting Slow LACPDUsF - Device is requesting Fast LACPDUsA - Device is in Active mode P - Device is in Passive modeChannel group 19LACP port Admin Oper Port PortPort Flags State Priority Key Key Number StateGi0/1/6 FA hot-sby 32768 0x13 0x13 0x47 0x7Gi0/1/7 SA bndl 32767 0x13 0x13 0x48 0x3DAdditional References
The following sections provide references related to the EtherChannel Flow-based Limited1:1 Redundancy feature.
Related Documents
Standards
No new or modified standards are supported by this feature, and support for existing standards has not been modified by this feature.
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MIBs
RFCs
No new or modified RFCs are supported by this feature, and support for existing standards has not been modified by this feature.
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Technical Assistance
Feature Information for EtherChannel Flow-based Limited 1:1 Redundancy
Table 1 lists the features in this module and provides links to specific configuration information.
Use Cisco Feature Navigator to find information about platform support and software image support. Cisco Feature Navigator enables you to determine which Cisco IOS XE software images support a specific software release, feature set, or platform. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.
Note
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