I need help understanding how a router learns a MAC address from a switch that doesn't appear to have it?
The router is C9500-40X, and the directly connected switch is WS-C3850-24XU.
From the router:
#sh mac add add 0000.00ff.ef52
Mac Addre...
The configuration is pretty standard, but I don't think it's something "lingering" anywhere; I think I mentioned in the original post that if I shut down the interface that connects the 3850, these MAC address entries disappear from the router's forw...
We do have port security enabled generally, though there's nothing connected to this switch yet except the management interface for a UPS.
The default configuration out to and end station looks like this though, unless it needs to be modified for a p...
"Ok, and you did show arp on router too and nothing there?"Correct. It's in the MAC forwarding table, but not in the arp table. (Any of them -- there are several VRFs configured, but I checked them all).
