Sunday, January 11, 2015

Nexus Virtual Port Chennel



















Enable required vpc and lacp features and assign a VPC domain id
7k1/2
feature vpc
feature lacp
vpc domain 1



Create L3 peer keepalive adjacency between 7K1 and 7K2 

7k1
peer-keepalive destination 10.0.0.1 source 10.0.0.2 vrf default

7k2
peer-keepalive destination 10.0.0.2 source 10.0.0.1 vrf default

Create L2 peer link between 7K1 and 7K2
7K1/2 {peer link}

int e2/25-26
shut
switchport mode trunk
spanning-tree port type network
speed 10000         {peer links need to be 10 gig links!}
channel-group 20 mode active

int po20
switchport mode trunk
spanning-tree port type network
vpc peer-link

int e2/25-26
no shut

Now configure downstream port channels to 5Ks
7K1/2{port channel}
int e2/27
switchport mode trunk
channel-group 10 mode active

int p10
vpc 10

int e2/28
switchport mode trunk
channel-group 11 mode active

int p11
vpc 11

Now configure upstream port channels from 5Ks to 7KS. Normal Port Channel config.
5K1/2{port channel}
int e2/27
switchport mode trunk
channel-group 10 mode active

int p10
switchport mode trunk

int e2/28
switchport mode trunk
channel-group 11 mode active
int p11
switchport mode trunk


Verification commands

show vpc  {check 'peer adjacency formed ok', and 'peer is alive' over the L3 link. one device will be the vpc primary and other will be secondary.}

show vpc after bringing up  keepalives between management addresses. Note config consistency status is 'failed' as no peer link is configured
 
show vpc after bringing up the peer link



show cfs peers {CFS - Cisco Fabric Services protocol transports configuration synch info across the peer link for VPC} 
show port-channel usage 
show vpc consistency-parameters
N.B. If any consistency checks fail the secondary device will shut down vpc paired interfaces