[c-nsp] Constant output drops on etherchannel

[Robert VanOrmer]

I am experiencing a very similar issue on the C3750E platform w/ 12.2(52)SE.
We have 5 switches in a cluster, port-channeled with (2) Gig interfaces L2
to distro (6500's) with excessive output drops even at low utilization.  No
QoS enabled.  I am using the Cisco TwinGig Converter Modules for uplinks..
We have a TAC case open, but no progress yet.  I'd be interested in knowing
if you find a cause. I am going to try swapping GBICs over the weekend.

 

Thanks,

Rob

 

>Date: Fri, 14 Jan 2011 12:28:03 -0600

>From: Dan Letkeman <danletkeman at gmail.com>

>To: Phil Mayers <p.mayers at imperial.ac.uk>

>Cc: cisco-nsp at puck.nether.net

>Subject: Re: [c-nsp] Constant output drops on etherchannel

>Message-ID:

>             <AANLkTiktxHw2Za3yWjU4rmPaa3q_-EU7N_dKtxUgMaz=@mail.gmail.com>

>Content-Type: text/plain; charset=ISO-8859-1

> 

>3560 or 3560G.

> 

>(C3560-IPSERVICESK9-M), Version 12.2(53)SE2

> 

>Interface config:

> 

>interface Port-channel2

>switchport trunk encapsulation dot1q

> switchport trunk native vlan 3009

> switchport trunk allowed vlan 8,10,1008,1101,3009  switchport mode trunk
end

> 

>I see more output drops during higher traffic, but I still see drops during
low traffic rates.  Always more on one interface.

> 

>I do have auto qos enabled for some of the phones I have connected to the
switches, but I don't have any qos on the etherchannel trunks.

> 

>I'm just using the default etherchannel load balancing algorithm.

> 

>Thanks,

>Dan.