[c-nsp] 10 gig ethernet interface up, line protocol down on VSL connection

[Reinhold Fischer]

On Sat, Jul 10, 2010 at 3:00 AM, Church, Charles
<Charles.Church at harris.com> wrote:
> Anyone,
>
>        Ran into a weird issue today with a re-build of a VSS pair.  A botched IOS upgrade forced me to rebuild the pair.  Was going ok, but I'm having trouble getting the VSL link up between the two.  Switch 2 had the port channel for the VSL link up/up, but on switch 1, it stays up/down.  Adding a second 10 gig link to the port channel on each side resulted in both up/up on switch 2, and both up/down on switch 1.  It was working a month ago in a lab, the lab guys upgrading to SXI4 killed the config.  I'm starting from scratch.  I ran out of time today, didn't get a chance to see if the ints would come up if the 'switch virtual link 1' command wasn't on there, or check the logs.  Using 2 ints should have ruled out bad X2 modules.  Just wondering if anyone has seem something similar with VSS.
>
> Thanks,
>
> Chuck
>

Are you negotiating the channel (PAGP/LACP) or is it configured to
channel mode "ON"? IIRC Cisco recommends "ON" for the VSL. The
behaviour that you descibe looks like one interface is configured to
mode ON and the other end tries to negotiate the portchannel.

hth,

Reinhold