Weird Pinging and routes issue

[juchestyle]

We are installing new, NSX 6.4 with an ACI Underlay.

I am trying to ping 10.225.3.1 from outside the environment.  It does not ping.  However, when I force sync ESG02, while ESG02 is rebooting that IP address starts pinging.  It will only ping until ESG02 is back up and running.

What is going on? 

[juchestyle]

If we have two ESG edges, and one goes down and the ping starts, that means the other Edge has the route and the one that is rebooting doesn't?  Is the way to resolve this to get them to sync?

[Sreec]

Is there any chance you can provide a simple topology which explains current connectivity issue ? ACI being underlay , i'm hoping Edges are peered with ACI Leaf via OSPF/BGP ? Any EPG level protection involved for ESG external vlans ?