Vpc Peer-Gateway - Cisco 7206 - VXR Router Configuration Manual

Information About vPCs
S e n d d o c u m e n t c o m m e n t s t o n e x u s 7 k - d o c f e e d b a c k @ c i s c o . c o m
If one of the vPC peer devices fails, the vPC peer device on the other side of the vPC peer link senses
the failure by not receiving any peer-keepalive messages. The default interval time for the vPC
peer-keepalive message is 1 second, and you can configure the interval between 400 milliseconds and
10 seconds.
You can configure a hold-timeout value with a range of 3 to 10 seconds; the default hold-timeout value
is 3 seconds. This timer starts when the vPC peer link goes down. During this hold-timeout period, the
secondary vPC peer device ignores vPC peer-keepalive messages, which ensures that network
convergence occurs before vPC action takes place. The purpose of the hold-timeout period is to prevent
false-positive cases.
You can also configure a timeout value with a range of 3 to 20 seconds; the default timeout value is 5
seconds. This timer starts at the end of the hold-timeout interval. During the timeout period, the
secondary vPC peer device checks for vPC peer-keepalive hello messages from the primary vPC peer
device. If the secondary vPC peer device receives a single hello message, that device disables all vPC
interfaces on the secondary vPC peer device.
The difference between the hold-timeout and the timeout parameters is as follows:
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•
See the
keepalive messages.
Note Ensure that both the source and destination IP addresses used for the peer-keepalive messages are unique
in your network and these IP addresses are reachable from the VRF associated with the vPC
peer-keepalive link.
Use the command-line interface (CLI) to configure the interfaces you are using the vPC peer-keepalive
messages as trusted ports. Leave the precedence at the default (6) or configure it higher. The following
is an example of configuring an interface as a trusted port:
(config)# class-map type qos match-all trust-map
(config-cmap-qos)# match cos 4-7
(config)# policy-map type qos ingresspolicy
(config-pmap-qos)# class trust-map
(config)# interface Ethernet8/11
(config-if)# service-policy type qos input ingresspolicy
See the Cisco Nexus 7000 Series NX-OS Quality of Service Configuration Guide, Release 5.x, for
complete information on configuring trusted ports and precedence.

vPC Peer-Gateway

Beginning with Cisco NX-OS Release 4.2(1), you can configure vPC peer devices to act as the gateway
even for packets that are destined to the vPC peer device's MAC address.
Use the peer-gateway command to configure this feature.
Cisco Nexus 7000 Series NX-OS Interfaces Configuration Guide, Release 5.x
7-12
During the hold-timeout, the vPC secondary device does not take any action based on any keepalive
messages received, which prevents the system taking action when the keepalive might be received
just temporarily, such as if a supervisor fails a few seconds after the peer link goes down.
During the timeout, the vPC secondary device takes action to become the vPC primary device if no
keepalive message is received by the end of the configured interval.
"Configuring vPCs" section on page 7-30 for information on configuring the timer for the
Chapter 7 Configuring vPCs
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