Welcome, Guest. Please login or register.

Author Topic: "Potential CDP loop on"  (Read 2220 times)

pc_sg

  • Sr. Member
  • ****
  • Posts: 261
    • View Profile
"Potential CDP loop on"
« on: September 12, 2013, 11:54:44 AM »
Hi Remo,
on my "production" NeDi host (running 1.0.8-116, as read from nedi.pl), occasionaly I receive alert with some "Potential CDP loop on[/size]" warning.
Of course before there is the switch name, and after there is the switch port.

But I haven't found anything around in internet about this kind of problem (except if a router is connected between two switches, but is not my case)

My "test" 1.0.9-240 (that monitors the same devices) doesn't send any similar alert.

Strange...

In the meanwhile, yesterday I've tested unreachable device alerts on 1.0.9-240, rebooting a unused device. No alert message from 240, but from 116.
Launched moni.pl in interactive mode, and I've seen that the failing test number is always 1, it doesn't increase.
Something wrong in my configuration?

TIA!

Paolo
« Last Edit: September 12, 2013, 12:34:16 PM by pc_sg »

rickli

  • Administrator
  • Hero Member
  • *****
  • Posts: 2619
    • View Profile
    • NeDi
Re: "Potential CDP loop on"
« Reply #1 on: September 12, 2013, 08:13:05 PM »
The loop message indicates that CDP learned a neighbor with the same name as the device. Check what's connected to that interface and you'll be sure about it...

Where exactly do you see this failing test number? Check Monitoring-Setup if you don't get a message. By default no alerts are creat...which I think should be changed to at least generating events, hmm.
Please consider Other-Invoices on your NeDi installation for an annual contribution, tx!
-Remo

pc_sg

  • Sr. Member
  • ****
  • Posts: 261
    • View Profile
Re: "Potential CDP loop on"
« Reply #2 on: September 13, 2013, 10:08:51 AM »
The loop message indicates that CDP learned a neighbor with the same name as the device. Check what's connected to that interface and you'll be sure about it...

Where exactly do you see this failing test number? Check Monitoring-Setup if you don't get a message. By default no alerts are creat...which I think should be changed to at least generating events, hmm.


1) I don't identify any "strange" neightbor, every port indicated in the warnings result offline. "show cdp neightbors" shows only the parent switch, connected to right ports.
no warning in "show log". our logging configuration is "logging buffered 32000" that as default on console is debugging level.


How NeDi identify this wrong condition?


2) sent PM


Thanks!


Paolo

rickli

  • Administrator
  • Hero Member
  • *****
  • Posts: 2619
    • View Profile
    • NeDi
Re: "Potential CDP loop on"
« Reply #3 on: September 15, 2013, 10:51:31 AM »
1) Not sure why you saw this in 108. Could be an inconsistency, but I haven't seen any problems with CDP so far. Observe 109 and eventually compare with "sh cdp ne", if you see it again...

2) Sent reply
Please consider Other-Invoices on your NeDi installation for an annual contribution, tx!
-Remo

pc_sg

  • Sr. Member
  • ****
  • Posts: 261
    • View Profile
Re: "Potential CDP loop on"
« Reply #4 on: September 16, 2013, 09:38:23 AM »
Strange, but last time I've received CDP loop alert message, after looking immediately in log I saw the CDP loop errors...
So they was true!


Sorry for the false alarm.


Paolo