lacp port-channel on Nexus 7000

Unanswered Question
Mar 16th, 2010

I am trying to bring up an lacp port-channel on a Nexus 7000 ( eventually using vpc) and it wouldn't come up. This work when mode is set to on but once the word active is used, the physical ports goes into suspended state and the port-channel remains down.

I have checked all the parameters and the configuration on both Nexus are identical. Below is the config:


interface Ethernet10/37
  switchport
  switchport access vlan 1020
  speed 1000
  duplex full
  mtu 9216
  no shutdown


interface port-channel35
  switchport
  switchport access vlan 1020
  speed 1000
  duplex full
  mtu 9216

  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 0 (0 ratings)
Loading.
Ganesh Hariharan Tue, 03/16/2010 - 23:34

I am trying to bring up an lacp port-channel on a Nexus 7000 ( eventually using vpc) and it wouldn't come up. This work when mode is set to on but once the word active is used, the physical ports goes into suspended state and the port-channel remains down.

I have checked all the parameters and the configuration on both Nexus are identical. Below is the config:


interface Ethernet10/37
  switchport
  switchport access vlan 1020
  speed 1000
  duplex full
  mtu 9216
  no shutdown


interface port-channel35
  switchport
  switchport access vlan 1020
  speed 1000
  duplex full
  mtu 9216


Hi,


Check out the below link for configuring LACP in Nexus 7000


http://www.cisco.com/en/US/docs/switches/datacenter/sw/4_1/nx-os/interfaces/configuration/guide/if_portchannel.html#wp1216823


Hope to Help !!


Remember to rate the helpful post


Ganesh.H

n-magbade Wed, 03/17/2010 - 08:33

Thanks Ganesh,

I am aware of that link, the configuration is exactly as posted but something is preventing the channel from coming up. I have checked all the configurable parameters and they are the same. At this stage I don't know what else to check. I'll keep on looking and maybe open a ticket with TAC.

ARMANDO ALVARADO Mon, 08/30/2010 - 14:05

Are you connecting two nexus together or another switch upstream and why did you set the speed manual if it is a ten gig link. ?

justinlala Wed, 02/09/2011 - 16:37

This happens for 1 of 2 reeasons.


1: The physical port negotiated half-duplex (does not apply here due to configured duplex).

2: The connected device is not sending it's LACP due to a configuration error or no LACP support.


Solutions

Configure the Nexus to ignore this and bring the port up anyway, however this will more than likely not fix your problem.  The end device will still not function properly due to whichever case is true.

Configure the end device properly.  Sometimes something as simple as changing an LACP parameter to a different value and then changing it back can cause it to become active (I've seen this with IBM Power hardware).

Remove LACP from the port-channel (don't use active or passive).  This is the only solution if your host does not support LACP.


Basically, the port will stay suspended as long as it detects half-duplex or if it doesn't ever recieve any LACP framing from the host.


Hope this helps anyone that comes across this issue in the future.

Actions

This Discussion