Hello and thanks for any comments you offer.
I'm testing stacked 3750s at the distribution layer of a typical 3 layer network. I'm trying to leverage the redundancy of cross-stack etherchannel while eliminating the need to rely on the recovery process of spanning tree to the (L2) access layer.
In my testing so far I have found that when I take off-line (reload) a member switch of the 2 member stack the recovery of connectivity is quick (about a second or so.) However when I take off-line the master switch, the recovery time is about 15 - 20 secs and my OSPF neighbour (Canadian, eh?) adjacencies reset.
Couple of questions:
1. Is anyone using this design in production anywhere?
2. If so have you seen any issues?
3. Any comments on the longer recovery time when I lose the stack master?
This contradicts what we saw with our testing, however without knowing the full topology and what the various routers are its a bit difficult to comment.
Have you verified that the OSPF neighbors are NSF aware? Are you doing any summarisation further up the network that would hide the OSPF recovergence. I would probably perform the testing with a PC attached to the 3750 stack with multiple pings running to the various OSPF neighbors up the tree (do a traceroute and record the neighbors) and see if the behaviour shows any patterns?.