01-07-2010 10:07 AM - edited 03-04-2019 07:09 AM
During some tests (7206VXR NPE-G2), placing an interface GigabitEthernet in loop, the router was unstable and showed these error messages:
Dec 23 15:41:10: %CLNS-3-BADPACKET: ISIS: LAN L2 hello, Duplicate system ID detected from 001d.a19a.ac19 (GigabitEthernet0/3)
Dec 23 15:42:10: %CLNS-3-BADPACKET: ISIS: LAN L2 hello, Duplicate system ID detected from 001d.a19a.ac19 (GigabitEthernet0/3)
I’m looking for a BUG.
Somebody knows why this is happening? Is not recommended close loop in Ethernet interfaces with IS-IS?
Thanks.
Solved! Go to Solution.
01-07-2010 11:05 AM
Hello Erik,
>> During some tests, placing an interface GigabitEthernet in loop,
the message is originated from the fact that the router receives its own Hellos back.
We use ISIS and this is a sign of a bridging loop when it happens in a campus network.
Nothing to worry about you have made a loop and ISIS detected it.
I would say it is good news
if it happens in production it is bad news sign of a bridging loop as I've written before
Hope to help
Giuseppe
01-07-2010 11:05 AM
Hello Erik,
>> During some tests, placing an interface GigabitEthernet in loop,
the message is originated from the fact that the router receives its own Hellos back.
We use ISIS and this is a sign of a bridging loop when it happens in a campus network.
Nothing to worry about you have made a loop and ISIS detected it.
I would say it is good news
if it happens in production it is bad news sign of a bridging loop as I've written before
Hope to help
Giuseppe
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