Hi all,
Using the above image as a reference point, you can see that with the configuration guide for OTV best practice, we'll break inter-vlan routing between DCs.
Here are some logical steps one might take when troubleshooting this:
1. Why not remove the MAC ACL?
If we remove the MAC ACL our "DAL" ToR switches will learn the 0000.0c07.acee MAC address from two points: The OTV devices and from the DC core. We need to make sure that from a L2 forwarding perspective, the only path to the MAC address associated with the gateway is to the DC core.
2. Why not connect the OTV router to the core itself (with the MAC ACL removed)? That way, there are no L2 issues with MAC table instability?
The core is 40G and the ASR1002 only supports 1G connections. We have the ASR connected to the ToR switch as it's the only place to allow for 1G connectivity.
3. Why not disable HSRP on the 6500 side so that the MAC addresses are different?
If we have different MAC addresses, we'll have a scenario where host B will have two entries in it's local ARP table; one for the gateway in DAL and one for the gateway in CORP.
Note: I've gotten this to work by using this method, but in doing so I have to disable OTV's arp-nd-cache and configure the MAC ACL to block arp responses.
Now, for my question (about time!):
Does anyone have any advice on how to get this to work given this setup--WITHOUT having to disable arp-nd-cache?
