Our automation for configuring IRB "Anycast Gateways" on EVPN switches assumes the use of a "virtual-gateway-address" for the gateway address shared across the switches. That in turn requires that each participating device also gets a unique IP on the subnet, with a config like this:
root@LEAF2> show configuration interfaces irb unit 100 family inet
address 10.192.0.7/22 {
preferred;
virtual-gateway-address 10.192.0.1;
}This is but one option of how to configure this functionality. Compared to the other options it is best as it means each switch has it's own IP, we can be pinged remotely and used as a source of tests locally from the switch. However, in prepping for moving the current public1-[a|b]-codfw gateways to the new row-wide switches in codfw it's obvious that we can't spare sufficient IPv4 addresses to give every switch on the row its own unique IP on the subnet.
The best solution is to use the VGA / unique IP approach on the private vlans / where possible, and change the automation to configure only the anycast IP on the interface if that is all that is present on it in Netbox. Creating task to track progress.