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Author Topic: Multiple cdp neighbors on 1 interface  (Read 4566 times)

Mikeuyz

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Multiple cdp neighbors on 1 interface
« on: May 06, 2015, 04:45:56 PM »
Hi community,

Currently i'm stuck with the discovery of CDP neighbors.

When I run this on the switch I get multiple outputs on 1 single interface:
Code: [Select]
sw-**-42-mer-ams#show cdp neighbors
Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge
                  S - Switch, H - Host, I - IGMP, r - Repeater, P - Phone,
                  D - Remote, C - CVTA, M - Two-port Mac Relay

Device ID        Local Intrfce     Holdtme    Capability  Platform  Port ID
sw-**-32-ams    Fas 0/1           150              S I   WS-C3560- Gig 0/1
sw-**-30-ams    Fas 0/1           147              S I   WS-C3560- Gig 0/1
sw-**-36-ams    Fas 0/1           149              S I   WS-C3560- Gig 0/1
sw-**-40-ams    Fas 0/1           158              S I   WS-C3560- Gig 0/1
sw-**-34-ams    Fas 0/1           172              S I   WS-C3560- Gig 0/1
sw-**-38-ams    Fas 0/1           122              S I   WS-C3560- Gig 0/1


sw-**-42-mer-ams#show cdp neighbors detail  | include IP address
  IP address: ***.***.13.67
  IP address: ***.***.13.67
  IP address: ***.***.13.66
  IP address: ***.***.13.66
  IP address: ***.***.13.69
  IP address: ***.***.13.69
  IP address: ***.***.13.71
  IP address: ***.***.13.71
  IP address: ***.***.13.68
  IP address: ***.***.13.68
  IP address: ***.***.13.70
  IP address: ***.***.13.70

Unfortunately Nedi only shows 1 CDP neighbor and ignores the rest, is there any fixes for this?

Command I run is:
-bash-4.1$ /noc/nedi/nedi.pl -a ***.***.13.72 -v

CDP output
Code: [Select]
Write ArpND -------------------------------------------------------------------
WAND:0 new IPs and 0 updates written

RNBR:1 neighbors read

Thanks in advance.

dohco

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Re: Multiple cdp neighbors on 1 interface
« Reply #1 on: May 06, 2015, 06:37:25 PM »
Hi,
 I've got an answer from rickli in another thread (http://forum.nedi.ch/index.php?topic=1858.0) that should help you.

/Conny

Mikeuyz

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Re: Multiple cdp neighbors on 1 interface
« Reply #2 on: May 14, 2015, 08:33:58 PM »
Hi,
 I've got an answer from rickli in another thread (http://forum.nedi.ch/index.php?topic=1858.0) that should help you.

/Conny

Thanks for your reply, I will look in to it and try to apply the same.

rickli

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Re: Multiple cdp neighbors on 1 interface
« Reply #3 on: May 15, 2015, 08:34:40 PM »
 Generally those interfaces would be the exception, correct? Like a dozen or so tops?
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Mikeuyz

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Re: Multiple cdp neighbors on 1 interface
« Reply #4 on: May 28, 2015, 05:00:58 PM »
Generally those interfaces would be the exception, correct? Like a dozen or so tops?

Hi Rickli,  in this case there are more then 10 cdp neighbors on 1 interface.
« Last Edit: May 28, 2015, 05:05:13 PM by MikeyvanderWorp »

rickli

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Re: Multiple cdp neighbors on 1 interface
« Reply #5 on: May 29, 2015, 10:30:22 AM »
I meant how many interfaces do you have, where multiple neighbors occur? Should only be some on the hub-routers, correct?
Please consider Other-Invoices on your NeDi installation for an annual contribution, tx!
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Mikeuyz

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Re: Multiple cdp neighbors on 1 interface
« Reply #6 on: May 29, 2015, 03:29:18 PM »
I meant how many interfaces do you have, where multiple neighbors occur? Should only be some on the hub-routers, correct?

Hi rickli,

This is correct yes, but to give you some small example I have attached an picture of how it currently is.

KR,
Mikey

Kasper

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Re: Multiple cdp neighbors on 1 interface
« Reply #7 on: June 02, 2015, 11:42:24 AM »
I also have this kind of network setup. But I know that I will end up with about 20-30 switches behind a rented L2-connection. So I would say that i will not be limited to a dozen connections but could be quite a few in the end.

rickli

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Re: Multiple cdp neighbors on 1 interface
« Reply #8 on: June 02, 2015, 02:47:42 PM »
Ok, but they all connect to the same 2 or so router interfaces at the hub?

I'm only asking because of manageability, because you'll have to enable multiple neighbor support on those interfaces. You're problably not that enthusiastic, if you have to look after hundreds of such exceptions, whereas a handful is probably ok.

I don't want to enable it by default, to avoid duplicate neighbors if multiple discovery protocols are being used on a single interface.
« Last Edit: June 02, 2015, 11:49:42 PM by rickli »
Please consider Other-Invoices on your NeDi installation for an annual contribution, tx!
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