Symptom
In multisite environment traffic from an endpoint in site-1 doesn't reach a silent host in site-2.
Workaround
Configure the silent host to periodically send some traffic.
Further Problem Description
The issue is in multi-site on a Bridge Domain stretched between two sites with unicast routing enabled and an IP address programmed. The BD has unknown unicast flood set to proxy mode without ARP flooding.
With this configuration a SPINE switch doesn't send ARP glean traffic to another site because special GIPO multicast route missing tunnel interface to another site on all SPINE switches.
To verify this condition, on all SPINE switches check "show ip mroute 239.255.255.224 vrf overlay-1". Working condition: at least one SPINE switch in every site should have a tunnel interface in "Outgoing interface list". Bug condition: none of SPINE switches in the same site have tunnel interface in OIF list.
