Introduction
A virtual PortChannel (vPC) allows links that are physically connected to two different Cisco Nexus Series devices to appear as a single PortChannel to a third device. vPCs consist of two vPC peer switches connected by a peer link. Of the vPC peers, one is primary and one is secondary. The system formed by the switches is referred to as a vPC domain. The vPC domain includes both vPC peer devices, the vPC peer keepalive link, the vPC peer link, and all the PortChannels in the vPC domain connected to the downstream device.
This document explains the reason for getting error “vpc port channel mis-config due to vpc links in the 2 switches connected to different partners” while configuring vPC.
Problem
The host is connecting to the two Nexus switches above via 4 physical links; 2 links to first Nexus and 2 links to second Nexus switch. After configuring the switches user is getting error that vpc mis-config because switches are connected to different partners.
Configuration
Following is the vPC configuration of the devices.
N5k-01(config)#
interface Ethernet1/5
switchport mode trunk
switchport trunk native vlan 17
channel-group 60 mode active
interface Ethernet1/6
switchport mode trunk
switchport trunk native vlan 17
channel-group 60 mode active
interface port-channel60
switchport mode trunk
switchport trunk native vlan 17
speed 10000
vpc 60
N5k-02(config)#
interface Ethernet1/5
switchport mode trunk
switchport trunk native vlan 17
channel-group 60 mode active
interface Ethernet1/6
switchport mode trunk
switchport trunk native vlan 17
channel-group 60 mode active
interface port-channel60
switchport mode trunk
switchport trunk native vlan 17
speed 10000
vpc 60
Error Message
N5K-01# sh vpc 60
vPC status
----------------------------------------------------------------------------
id Port Status Consistency Reason Active vlans
------ ----------- ------ ----------- -------------------------- -----------
60 Po60 down* failed vpc port channel -
mis-config due to vpc
links in the 2 switches
connected to different
partners
Resolution
The error indicates that the cabling is incorrect, or the server is not configured properly. Basically the switch is seeing a different LACP system ID from the different links. To resolve this you need to ensure all 4 links on the host side are correctly configured in one bundle, not two.
Related Information
Virtual PortChannel Quick Configuration Guide
VPC on Nexus 5548 showing Error (Connected with Phycial Server)