Fibre Channel (SAN)

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tra
Occasional Contributor
Posts: 7
Registered: ‎03-10-2011

Telling difference between cable and SFP problems?

Hello,

The other day, I had an SFP which had gone bad, it turned out. There is a detailed description here: http://troelsarvin.blogspot.com/2011/10/what-dying-sfp-looks-like.html

This made me wonder: Would the graphs / error count picture had been different if it had been a cable problem instead of an SFP problem?

--

Troels

Valued Contributor
Posts: 931
Registered: ‎12-30-2009

Re: Telling difference between cable and SFP problems?

Perhaps not THE answer to your question but intresting nontheless is this blog posting >> http://www.thesanman.org/2011/01/crc-errors-code-violation-errors-class.html

Usually sfp problems can be detected by dropping in speed (if set on AN) and powerlevels. I'am using a figure of powerlevels in near 400 uW as "normal".

tra
Occasional Contributor
Posts: 7
Registered: ‎03-10-2011

Re: Telling difference between cable and SFP problems?

Thanks for the link - I'll read it tonight.

About power levels: Is there a way to monitor this? An snmpwalk doesn't seem to reveal anything power-related, but maybe I overlooked something.

Valued Contributor
Posts: 931
Registered: ‎12-30-2009

Re: Telling difference between cable and SFP problems?

From the FCMGMT mib you could try to work with loss of signal and loss of sync.

OID's are resp.  .1.3.6.1.3.94.4.5.1.43 and .1.3.6.1.3.94.4.5.1.44

Haven't found OID's with regards to the sfp yet.

Valued Contributor
Posts: 931
Registered: ‎12-30-2009

Re: Telling difference between cable and SFP problems?

Found a Brocade document about DCFM in which the outline the possibility to monitor SFP powerlevels.

You'll need the fabric watch license for it to work.

http://www.brocade.com/downloads/documents/white_papers/DCFM_PerfMon_Thresholds_GA-BP-247-00.pdf

If you got Fabric watch and configured it to your needs, you can only monitor on the event created when going through thresholds.

OID FW subtree is located on  .1.3.6.1.4.1.1588.2.1.1.1.10

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