ed vPCs to bounce or VLANs to be suspended. My recommen- dation is to change anything even remotely relating to vPCs during an approved change control window. Nexus Design Features The first thing you should check when your vPCs don't work is the show vpc command. Here's an example of a vPC that's working. If you had 30 vPCs, each would be listed in the output of this command. Notice that the status of the peer link is shown as well. The output from these commands may differ based on the switch, OS revision, and features in use. NX-7K-2-Annie(config-if)# sho vpc Legend: (*) - local vPC is down, forwarding via vPC peer-link vPC domain id : 100 Peer status : peer adjacency formed ok vPC keep-alive status : Suspended (Destination IP not reachable) Configuration consistency status: success Type-2 consistency status : success vPC role : secondary Number of vPCs configured Peer Gateway : Disabled Dual-active excluded VLANs vPC Peer-link status Status Active vlans vPC status Status Consistency Reason Active vlans success success The next command you should grow to love when troubleshooting vPCs is the show vpc consistency-parameters command. When you specify the vPC you're struggling with, you will be treated to a list of every little detail concerning the items that must match. Here's the output for a working vPC: NX-7K-2-Annie(config-if)# sho vpc consistency-parameters vpc 10 Legend: Type 1 : vPC will be suspended in case of mismatch Local Value Peer Value STP Port Type Default Default STP Port Guard STP MST Simulate PVST Default Default Speed 1000 Mb/s 1000 Mb/s Duplex Chapter 18: Cisco Nexus Port Mode access access Native Vlan Allowed VLANs Local suspended VLANs Now let's change something on one side and see what happens: NX-7K-2-Annie(config-if)# int e3/23 NX-7K-2-Annie(config-if)# speed 100 The output of the show vpc command will show us that the vPC is now broken: NX-7K-2-Annie(config-if)# sho vpc Legend: (*) - local vPC is down, forwarding via vPC peer-link vPC domain id : 100 Peer status : peer adjacency formed