Nexus 7700 Routing

[jamie.gleeson]

Hello

We are migrating from a pair of Cat 6500s to a pair of Nexus 7700s. The 7700 switches are configured with a Layer-2 peer-link but there is no Layer-3 link between them (with the exception of the peer keep-alive connection). We are have some down stream EIGRP and OSPF neigbors with the 6500s and will be migrated to the 7700s. My question is: do I require a Layer-3 link between the 7700s even though the EIGRP and OSPF neigbors are down stream and not directly connected to these Nexus switches.

Thanks

Jamie

[balaji.bandi]

If i understand your question correctly.

you are migrationg Cat 6500s to a pair of Nexus 7700s ( so you looking like a like migration) and decommission 6500 is this correct. if not do not go to next steps and explain more.

There are different approaches you can do here is : (easy one is)

1. you need to have L3 interface and point to point interface configured and  in shutdown mode

2. example 6500 VLAN 10 - same will be created in nexus and p2p ip configured

3. once you ready for cutover, 6500 VLAN 10 shutdown, and point to point interface , bring up VLAN 10 and p2p interface in nexus

4. Move the down stream switch link to Nexus and test it. ospf/eigrp neighbourship.

[tellis002]

Overall, 7k's are quite the machine, so I can't imagine your not going to be doing routing on them.  Therefore, I'm sure you are going to want to make them neighbors.

Best practice right now is to have a Layer 2 (port-channel) between the two peered 7k's, most likely the peer link (not the keepalive link) split across the blades.  Along with having a physical separate Layer 3 (port-channel) between the two 7k's as well, split across the blades.  

There are some newer codes that allow some routing over the peer-link, but i would not go that route yet (no pun intended ;), that is why it is currently best practice to have different physical connections.