Nexus 1000v Port-Channel Best Practices

[mwronkow]

• Introduction
• Prerequisites
• Related Information

Introduction

The Nexus 1000v requires port-channels for port-profiles containing more than one interface per host. This document describes best practices for deploying port-channels on N1k. In Nexus 1000v the Virtual Supervisor Module (VSM) manages the Cisco Nexus 1000V Series switch VEMs. The Virtual Ethernet Module (VEM) executes inside the Cisco Nexus 1000V Series switch hypervisor.

Note: Please let me know if your topology is not covered by the examples in this document.

Prerequisites

Understanding of Nexus 1000v and Port-channel basics.

Related Information

Configure and Verify LACP Offload on Nexus 1000v

Nexus 1000v Log Collection

[michael.dickinson]

A very useful document but misses off the topology of a rack mount server connecting to a single upstream switch. I assume from other cisco documentation that in this scenario you should just use:

channel-group auto mode on

but it would be good to get clarification on that.

Thanks,

Michael

[mwronkow]

Hello Michael,

For a host connected to a single upstream swith you can use any method - mode on, lacp or mac-pinning.  LACP would be considered best-practice.  It was not included in the document as having a single upstream switch is a single point of failure.  I will add this to the next revision.

Matthew

[sokarlsson]

Great doc!

Would be nice to examples of N1k <-> Dell/HP blade chassis and B22 FEX blades.
My guess would be LACP in 1000v / enhanced vPC + LACP in N5k/N7k?

[Tobias Heisele]

I want fex and portchannel number to be the same (for easier troubleshooting). Is there a possibility to "block" po1+2", that these two numbers are not use in auto mode?

[mwronkow]

Hello T.Kraemer,

So you would like PO numbers to begin at 3?  You could simply:

int po 1

shut

int po 2

shut

which will result in PO3 as the first port-channel.

Or if you wish to predefine the port-channels, then do the following before adding the host to N1k dvs.

vem 7

  host vmware id b0e12784-911d-11df-2000-000000000004   <----esxcfg-info | grep "BIOS UUID"  or vemcmd show card

int po 102

inherit port-profile system-uplink

vem 7

--> Add the host to N1k now.

# sh port-chan summary | inc 102

102   Po102(SU)   Eth      NONE      Eth7/2(P) 

[Tobias Heisele]

Hi Matthew,

when I shut down the first 2 portchannels and a host is added through vcenter, the next unused portchannel will be used?

That would be great!

[mwronkow]

That is correct.

[mnisk-ssi]

5 stars.  Awesome.  Any updates planned or required for this doc?  Thanks!