Validating VPC / Port Channels in NX-OS

Let's say you are coming into an environment fresh, and you want to learn the vPC  topology - or just troubleshoot . . . let's scope this out with some handy NX-OS commands.

N7K# show vpc 

vPC Peer-link status
---------------------------------------------------------------------
id   Port   Status Active vlans   
--   ----   ------ --------------------------------------------------
1    Po1    up

We see that the vPC peer link is Port-Channel 1. What members are in that port channel?

N7K# show run int Po1 membership
!Command: show running-config interface port-channel1 membership
!Time: Mon Apr 25 10:26:00 2011
version 5.0
interface port-channel1
  description vPC PEERLINK
  switchport
  switchport mode trunk
  vpc peer-link
  spanning-tree port type network
  mtu 9216
interface Ethernet1/1
  description  N7K-2 Eth1/1
  switchport
  switchport mode trunk
  rate-mode dedicated force
  mtu 9216
  channel-group 1 mode active
  no shutdown
interface Ethernet3/1
  description N7K-2 Eth3/1 
  switchport
  switchport mode trunk
  rate-mode dedicated force
  mtu 9216
  channel-group 1 mode active
  no shutdown

Cool. No what vlans are riding over the Peer link?
 Nice. Okay. What is this 7K's vPC role?   

N7K# show interface po1 switchport
 Name: port-channel1
  Switchport: Enabled
  Switchport Monitor: Not enabled
  Operational Mode: trunk
  Access Mode VLAN: 1 (default)
  Trunking Native Mode VLAN: 1 (default)
  Trunking VLANs Enabled: 1-3967,4048-4093
  Administrative private-vlan primary host-association: none
  Administrative private-vlan secondary host-association: none
  Administrative private-vlan primary mapping: none
  Administrative private-vlan secondary mapping: none
  Administrative private-vlan trunk native VLAN: none
  Administrative private-vlan trunk encapsulation: dot1q
  Administrative private-vlan trunk normal VLANs: none
  Administrative private-vlan trunk private VLANs: none
  Operational private-vlan: none



N7K# show vpc role                            vPC Role status
----------------------------------------------------
vPC role                        : primary                      
Dual Active Detection Status    : 0
vPC system-mac                  : 00:23:04:ee:be:0a            
vPC system-priority             : 32667
vPC local system-mac            : a8:b1:d4:55:4e:42            
vPC local role-priority         : 16332
DENVWSW0001-INTERNAL#

Right then. What about the keep alive link? what are the IPs and the interfaces?

N7K# show run vpc
!Command: show running-config vpc
!Time: Mon Apr 25 10:37:16 2011
version 5.0
feature vpc
vpc domain 10
  peer-switch
  role priority 16332
  peer-keepalive destination 10.1.1.2 source 10.1.1.1 vrf keepalive
  peer-gateway
  reload restore
N7K# show ip int br vrf keepalive

IP Interface Status for VRF "VPC-KEEPALIVE"(5)
Interface            IP Address      Interface Status
port-channel5        10.1.1.1   protocol-up/link-up/admin-up

N7K# show run int po5 memebership

!Command: show running-config interface port-channel3 membership
!Time: Mon Apr 25 10:42:36 2011
version 5.0(3E4)
interface port-channel5
  description keepalive link
  vrf member keepalive
  ip address 10.1.1.1/30
interface Ethernet2/1
  description to N7K-2
  channel-group 5 mode active
  no shutdown

With this handful of handy commands, you can see what is going on with vPC and port-channels in a Jiffy. I do notice in NX-OS  that the port-channel interfaces are missing when you want to view your 'logical' nieghbors with cdp.

N7K# show cdp neigh interface ?
  ethernet  Ethernet IEEE 802.3z
  mgmt      Management interface

So you have to use the membership command (referenced above) to find out the physical interfaces that are bound to the port-channel and issue the show cdp neigh on those interfaces.