Re: Strange CDP Observation

Nate,

Have observed this in native L2 Cisco networks too (without hub)
Even once in practice labs too..-:)

A complete reconfiguration helped in my case !

Tharak.

On Sun, Nov 29, 2009 at 7:04 AM, Nate Lee <natetlee_at_gmail.com> wrote:

> I also saw this same effect of a switch appearing as its own neighbor when
> using 2 links in a flex link setup to connect to a non-Cisco switch. The
> switch saw itself as a CDP neighbor on each flex link port through the 3rd
> party switch.
>
> Nate
>
> On Sat, Nov 28, 2009 at 5:40 PM, Joe Astorino <jastorino_at_ipexpert.com
> >wrote:
>
> > Yes you have a loop somewhere in your L2 network that you need to trace
> > down. I have seen this before and it turned out to be a hub stuck
> somewhere
> > in the middle of a loop.
> >
> > Switch1--hub--Switch1
> > ------Original Message------
> > From: Ernest McCaleb
> > Sender: nobody_at_groupstudy.com
> > To: Felix Nkansah
> > Cc: cisco-nsp_at_puck.nether.net
> > Cc: CCIE Groupstudy
> > ReplyTo: Ernest McCaleb
> > Subject: Re: Strange CDP Observation
> > Sent: Nov 28, 2009 6:24 PM
> >
> > There is a loop someplace.
> >
> > Ernest #21508
> >
> > On Sat, Nov 28, 2009 at 5:42 PM, Felix Nkansah <felixnkansah_at_gmail.com
> > >wrote:
> >
> > > Hi Team,
> > >
> > > One of my field engineers at a remote site has reported a problem to
> me,
> > > one
> > > which I find rather strange but yet to confirm for myself.
> > >
> > > A Catalyst 2960 switch at the remote site is linked to a switch at a
> > > Central
> > > site via radio (bridged).
> > >
> > > However, besides the fact that connectivity tests between the two sites
> > are
> > > failing, his observation is that when he issues the "SHOW CDP NEI"
> > command
> > > on the remote C2960 switch, he sees the switch itself appearing as its
> > > neighbor rather than the other switch at the central location which is
> > > typically the output he expected.
> > >
> > >
> > > I have personally never seen a Cisco device showing itself as it's own
> > > neighbor in a 'show cdp neighbor' output.
> > >
> > > What do you know to be the cause of this problem?
> > >
> > > Thanks.
> > >
> > >
> > > Blogs and organic groups at http://www.ccie.net
> > >
> > > _______________________________________________________________________
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> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> >
> >
> > --
> > Ernest McCaleb
> >
> >
> > Blogs and organic groups at http://www.ccie.net
> >
> > _______________________________________________________________________
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> >
> >
> >
> >
> >
> >
> >
> >
> >
> > Regards,
> >
> > Joe Astorino - CCIE #24347 R&S
> > Technical Instructor - IPexpert, Inc.
> > Cell: +1.586.212.6107
> > Fax: +1.810.454.0130
> > Mailto: jastorino_at_ipexpert.com
> >
> >
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> >
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>
>
> Blogs and organic groups at http://www.ccie.net
>
> _______________________________________________________________________
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Received on Sun Nov 29 2009 - 08:34:28 ART