From: Brian McGahan (brian@cyscoexpert.com)
Date: Fri Sep 20 2002 - 21:26:21 GMT-3
The reason the CDP packets will not transit the catalyst switch
is because the catalyst switch *is* the CDP neighbor. The reason the
CDP can transit the Frame-Relay and ATM provider network is because the
CDP info is contained in the SNAP header. Were there to be a cisco
switch in the transit path that is running CDP, the CDP packet would
terminate on that switch.
Brian McGahan, CCIE #8593
Director of Design and Implementation
brian@cyscoexpert.com
CyscoExpert Corporation
Internetwork Consulting & Training
http://www.cyscoexpert.com
Voice: 847.674.3392
Fax: 847.674.2625
> -----Original Message-----
> From: Larry Roberts [mailto:larryr@netbeam.net]
> Sent: Friday, September 20, 2002 1:51 PM
> To: Brian McGahan; 'kevin'; ccielab@groupstudy.com
> Subject: Re: cdp nei on FR
>
> Brian,
>
> I think what Kevin is asking is how can you see a neighboring Frame
Relay
> router via CDP even though it is not truly a DIRECTLY CONNECTED
device.
> The
> Frame Relay switch interconnects routers on a Frame Relay cloud.
Whereas,
> in
> Ethernet when two routers are interconnected via a Catalyst switch and
on
> the same VLAN, the output of the show cdp neighbors command on the
routers
> will show only the switch, not the neighboring router. Catalyst
switches
> do
> not pass CDP information, but a Frame Relay switch will. I believe ATM
> switches will also, but don't quote me on that. :-)
>
> Sincerely,
> Larry Roberts
> CCIE #7886 (R&S / Security)
>
>
> ----- Original Message -----
> From: "Brian McGahan" <brian@cyscoexpert.com>
> To: "'kevin'" <kevinjin@sh.cngb.com>; <ccielab@groupstudy.com>
> Sent: Friday, September 20, 2002 9:21 AM
> Subject: RE: cdp nei on FR
>
>
> > Kevin,
> >
> > CDP will run on any media that supports a SNAP header. CDP is
> > globally enabled by default. To enable/disable it use the global
command
> > '[no] cdp run'. To enable/disable it on an interface, use the
interface
> > command '[no] cdp enable'
> >
> > HTH
> >
> > Brian McGahan, CCIE #8593
> > Director of Design and Implementation
> > brian@cyscoexpert.com
> >
> > CyscoExpert Corporation
> > Internetwork Consulting & Training
> > http://www.cyscoexpert.com
> > Voice: 847.674.3392
> > Fax: 847.674.2625
> >
> >
> > > -----Original Message-----
> > > From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On
Behalf
> > Of
> > > kevin
> > > Sent: Friday, September 20, 2002 10:44 AM
> > > To: ccielab@groupstudy.com
> > > Subject: cdp nei on FR
> > >
> > > Hi,
> > >
> > > How can routers become cdp nei on FR ?
> > >
> > > Thanks
> > >
> > > Kevin
This archive was generated by hypermail 2.1.4 : Mon Oct 07 2002 - 07:43:58 GMT-3