I'm fairly new to the Nexus line and am trying to wrap my head around features and operation of them. I've been going though different remote sites that have them and noticed that they are not all set up the same concerning vPC and would like to know what is the best practice and why you would want to configure them a certain way.
All of the 5000s are configured with a peer link. I understand the concept of this. This is how the switch is able to acheive the vPC without causing loops.
All of the 5000s are configured with a peer link keepalive as well and this I don't quite grasp and in addition not all of the remote sites have the peer link configured the same way.
Some have a seperate vrf just for the peer link keepalive and are directly connected to the other 5000 using the a VLAN 996 and a VLAN 997. VLAN 996 has an IP on both of the 5000s in the same subnet and VLAN 997 is named VPC-Peer-Link with no IP and both VLANs are carried through a trunk directly to the other 5000. Others use the Management vrf and are connected to the other 5000 though another layer 2, 2960 switch ( both 5000s have their mgmt0 port patched into the same VLAN).
First - what is the keepalive link needed for if we have a configured vpc peer link? Redundacy?
Also, what is the preferred method to set this up or are both ways acceptable?