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Re: [c-nsp] SFP DOM SNMP Polling?


From: Jared Mauch <jared () puck nether net>
Date: Tue, 22 Nov 2016 10:35:47 -0500


On Nov 22, 2016, at 9:32 AM, Tim Durack <tdurack () gmail com> wrote:

I have a vendor that does not support SFP DOM SNMP polling. They state this
is due to EEPROM read life cycle. Constant reads will damage the SFP.

We SNMP poll SFP DOM from Cisco equipment without issue.

Not heard this one before. Trying to see if there is some validity to the
statement. Thoughts?

It’s entirely possible some people implement it poorly and the read cycles count.  With 100k cycles somewhat typical 
for those bytes, it’s certainly something that could be seen if polling every 5 minutes in 347 days, but I think that’s 
a datapoint that most SFPs are warranted for much longer than 347 days.

As the DDM data is stored not at 0x50 but at 0x51/0x52 in optics this is more likely done with a micro controller 
presenting the ram backed data via reads to/from those specific bytes.

- Jared

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