Hello,
Don't know why my previous post didn't go through. Here we go again.
If you want to use IRB on MC-LAG peer we need to come up with a mechanism to provide gateway address to downstream hosts/clients. There are two way we can do that.
1) Configure different IP addresses on IRB or RVI interfaces, and run Virtual Router Redundancy Protocol (VRRP) over the IRB or RVI interfaces. The virtual IP address is the gateway IP address for the MC-LAG clients.
2) Configure the MAC address synchronization feature using the mcae-mac-synchronize statement, and configure the same IP address on each of the IRB or RVI interfaces on the MC-LAG peers. This IP address is the gateway IP address for the MC-LAG clients. In case you want to use same IP address on both IRB "mcae-mac-synchronize" knob is mandatory.
Mcae-mac-synchronize’ knob is for synching irb mac between PE’s in MCLAG A/A. You can have same IRB IP address on both PE’s and on enabling this knob, lowest IRB MAC address among PE’s, will be synced to other PE and will be published to CE’s for gateway MAC. Hence CE devices will be sending traffic with the lowest IRB mac. If lowest IRB MAC device goes down, current active PE will send it’s own IRB mac as gateway mac to CE devices.
Refer: https://www.juniper.net/documentation/en_US/junos-space-apps/connectivity-services-director2.0/topics/concept/multichassis-link-aggregation-groups-overview.html
PS: Please accept my response as solution if it answers your query, kudos are appreicated too!
Thanks
Vishal