[c-nsp] switch interface down but passing traffic

[Eric Gauthier]

Gert,

The only time I've seen something (legitimately) similar is when
the interface is configured for port monitoring (older 3500xls)
or Span.

Eric Gauthier


On Wed, Feb 02, 2011 at 08:35:21AM +0100, Gert Doering wrote:
> Hi,
> 
> got hit by a quite interesting bug in the CBS3020 switches yesterday:
> 
> sw2-int.blau#sh int g0/24
> GigabitEthernet0/24 is up, line protocol is down (disabled) 
> ...
>   5 minute input rate 1759000 bits/sec, 350 packets/sec
>   5 minute output rate 2122000 bits/sec, 383 packets/sec
> 
> this interface is "up/down" since about a day, and happily forwarding
> packets.  It does *not* do CDP, which is how we noticed (we monitor
> CDP relationships to see topology/device changes).
> 
> This is a WS-CBS3020-HPQ, running cbs30x0-ipbase-mz.122-53.SE1, and
> the interface config is really trivial:
> 
> interface GigabitEthernet0/24
>  description Trunk to sw1-int.blau:gi0/24
>  switchport trunk allowed vlan 79-82,87-89
>  switchport mode trunk
>  media-type internal
> end
> 
> ... and no matter what I do (shut/no shut on either end, change 
> media-type to external/internal) will bring the port back to up/up.
> 
> Shutting down the other end will bring the port to down/down, so it's
> still noticing something :-) - but unshutting will bring it back to up/down.
> 
> "errdisable autorecovery" didn't help either.
> 
> Weird, eh?
> 
> 
> Question to the list: has one of you seen this, and found a way to un-stick
> the port without rebooting?
> 
> gert
> -- 
> USENET is *not* the non-clickable part of WWW!
>                                                            //www.muc.de/~gert/
> Gert Doering - Munich, Germany                             gert at greenie.muc.de
> fax: +49-89-35655025                        gert at net.informatik.tu-muenchen.de



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