[c-nsp] loop guard still useful?

Michele Bergonzoni bergonz at labs.it
Mon Jan 18 06:46:40 EST 2016

> On A-B link, where A=>B works but A<=B does not, A will go down and A
> will assert RFI or remote fault indicator on the line. B will receive
> this, and go down as well.

You're right as usual. I actually happened to see a 1000baseLX port in dispute a few years ago, so you made me dig through old emails and tickets.

It was a 6500 facing a 3750, and it was because MSTP BPDUs where incorrectly tagged, probably due to CSCta17209, we fixed upgrading the 3750.

Probably UDLD wouldn't have helped either.


Ing. Michele Bergonzoni - Laboratori Guglielmo Marconi S.p.a.
Phone:+39-051-6781926 e-mail: bergonz at labs.it

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