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New Member

configure vPC-HM for Nexus 1000v onUCS

Hi guys,

Evnironment: UCS 5108 chassis with two FI, Nexus 1000v on ESXi 4 on two B200, M71KR CNA.

I am following this cisco paper:

my previous experience, you need to configure PortChannel on both side of switches for form a working PortChannel. my question when I configure vPC-HM on the Nexus 1000v:

1, is there any configuration required on the FI or the uplink switch? for example, the uplink switch needs to be configured to form a PortChannl as well?

2, does it make a difference if the FI is in switch mode or end-host mode? I couldn't find how to configure PortChannel on the FI.

thank you


Cisco Employee

Re: configure vPC-HM for Nexus 1000v onUCS

There should not be a difference between end-host mode or switch mod for this configuration. If you are having problems getting your port-channel to form on the N1Kv there a few things you can look at some of it is UCSM version dependent.

If you are using port-profile config with channel-group auto mode on subgroup cdp you need to enable CDP on the UCS Service Profile NICS for each host. Enabling CDP on the VNIC I think requires 1.02d code or later.  If you are using an earlier code you need to manually define the subgroup ID for each VETH on the N1K corresponding to your Host uplinks.

I believe the new recommended method is to use channel-group mode on mac-pinning which is available AV N1Kv release.

If you do show int brief on the N1Kv and your  Port-Channel interfaces are all up then you are good to go.

New Member

Re: configure vPC-HM for Nexus 1000v onUCS

Thanks for your reply. I can't find any reference about mac-pinning command for creating PortChannels, did u mean static pinning? could you show me the relevant doc?

Cisco Employee
New Member

Re: configure vPC-HM for Nexus 1000v onUCS

thanks, I was looking at the Nexus 1000v Interface Configuration Guide, there is a whole section regarding port channel, but not mentioning mac-pinning, probably because it's a port-profile command

I wonder why it is "new recommended" way for PortChannel as you said, what is the benefit doing this way? All I can find in the doc is that it is used when upstream switch does not support port channel:

mac-pinning—Specifies that Ethernet member ports are assigned to subgroups automatically, one subgroup per member port. This option is used if the upstream switch does not support port channels.



Re: configure vPC-HM for Nexus 1000v onUCS


mac pinning is a new feature of the latest software release and therefore wasn't available previously. Before that, VPC HM was recommended in the prior release.

The benefit of using mac-pinning is you don't create separate subgroups for each uplink interface. Hence less complexity and configuration. Essentially VPC HM and mac-pinning work in similar ways anyway.



Cisco Employee

Re: configure vPC-HM for Nexus 1000v onUCS

Here's a quick video I put together on MAC pinning and 1000v.  Have a watch.


Re: configure vPC-HM for Nexus 1000v onUCS


Unfortunately what the configuration guide does not indicate is that although in earlier releases prior to 1.02d where the VNIC doesn't support CDP, the only way to successfully configure vPC-HM was to configure the port-profile system-uplink with CDP and also manually define the subgroup ID for each VETH.  This may not be case in later releases but this was what I discovered, and Cisco recommended to do as shown the extract below:-

port-profile system-uplink

  capability uplink

  vmware port-group dvs-system-uplink

  switchport mode trunk

  switchport trunk allowed vlan 1,32,129-130,136-137,900-901,2901

  channel-group auto mode on sub-group cdp

  no shutdown

  system vlan 136-137,900-901

  state enabled

interface Ethernet3/1

  inherit port-profile system-uplink

  description ESX07 vmnic0

  sub-group-id 0



New Member

Re: configure vPC-HM for Nexus 1000v onUCS

vPC-HM does not require a port-channel configuration on the upstream switch nor does mac-pinning. The northbound device sees these interfaces as host ports.

vPC-HM did require the upstream switch to support CDP, mac-pinning does not.