Users Guide

Link Aggregation 1039
console(config-vpc 1)#role 10
console(config-vpc 1)#exit
Modifications to priority and timeout interval are effective only before the
keep-alive protocol is enabled. Once enabled, MLAG switches contest in
an election to select the primary and secondary switch. The election is
non-preemptive.
If configured, the system virtual MAC address MUST be the same on both
of the MLAG peers.
3 Configure the peer-link. On each MLAG peer:
• Configure a port-channel as the peer-link for the MLAG devices. It is
recommended that the administrator use dynamic LAGs as port-
channels.
• It is strongly recommended that the MLAG peer LAG consist of
multiple physical links with sufficient bandwidth to carry all MLAG
traffic expected to be carried by either MLAG peer.
• Enable trunking on the peer-link. Remove any non-MLAG VLANs
from the peer-link trunk port. VLANs cannot be configured to contain
both MLAG ports and non-MLAG (non-redundant) ports.
• Ensure that the peer-link has a native VLAN configured.
• Optionally, configure UDLD on the peer-link to detect and shut down
unidirectional links. UDLD should be used on any fiber ports, as fiber
ports can operate in a unidirectional mode.
• Associate the port-channel with physical links.
console(config)#interface port-channel 1
console(config-if-Po1)#description “MLAG-Peer-Link”
console(config-if-Po1)#switchport mode trunk
console(config-if-Po1)#vpc peer-link
console(config-if-Po1)#exit
console(config)#interface range te1/0/1-2
console(config-if)#channel-group 1 mode active
console(config-if)#description “MLAG-Peer-Link”
console(config-if)#udld enable
console(config-if)#udld port aggressive
console(config-if)#exit
When the peer-link is configured, the MLAG component disables MAC
learning on the port-channel configured as the peer-link.