Users Guide

Link Aggregation 1077
to the primary switch for handling. FDB entries learned on MLAG
interfaces are synced between the two devices.
console(config)#interface range gi1/0/1-4
console(config-if)#channel-group 2 mode active
console(config-if)#exit
console(config)#interface range gi1/0/5-8
console(config-if)#channel-group 3 mode active
console(config-if)#exit
console(config)#interface port-channel 2
console(config-if-Po2)#switchport mode trunk
console(config-if-Po2)#vpc 1
console(config-if-Po2)#exit
console(config)#interface port-channel 3
console(config-if-Po3)#switchport mode trunk
console(config-if-Po3)#vpc 2
console(config-if-Po3)#exit
Switch Firmware Upgrade Procedure
MLAG supports minimally intrusive firmware upgrade of the MLAG peer
switches. In most cases, protocols with retransmission capability, e.g., TCP,
will experience a limited interruption of service. Network operators must
ensure that the aggregate bandwidth in use on the MLAG can be supported
on a single MLAG peer.
During the upgrade, traffic that is forwarded to an MLAG switch during
reboot will fail over to the MLAG peer. The traffic disruption is limited to the
time required for devices dual attached to the VPC device pair to detect the
link-down and link-up events and to rehash the traffic.
Use the show vpc brief command to determine which switch is the primary
switch. This procedure upgrades the primary switch first, followed by the
standby switch. Following this order reduces the reconvergence time to the
minimum.
Upgrade Steps
1 Download the new code and activate it on both the Primary (VP) and
Secondary (VS) MLAG peer switches.
2 Enable DCPDP (if disabled) on both the switches and save the running-
config.