From: hulbertj@comcast.net
Date: Thu Jul 14 2005 - 13:55:48 GMT-3
I've seen symbol errors on some of the lower Catalyst Switch models (2950T, 2970), when they are connected to non-Cisco devices. I believe their PHY chip is less tolerent of errors. I would also see a bunch of bogus dynamic MAC addresses being added to the table on this interface. It might be hard to determine this, if the Gig links are connected to (trunked) to a bunch of access switches. You might also be seeing FCS and Alignment errors too.
Symbol errors - Ethernet uses the Manchester encoding to encode data as symbols before transmission. The destination reverse encodes the symbols back into data. Some code symbols may become invalid, causing the "symbol errors".
Jerry
-------------- Original message --------------
> Without a doubt! The Sup3 seem to have some problematic issues, that
> usually require a sup replacement when they start experiencing CRC
> errors. Have seen a lot of Symbol errors on gig links as well, although
> never gotten a good explanation from Cisco on why they occur so
> frequently.
>
> One thing I would suggest is to have a field analysis test done when
> sending into Cisco for an RMA. I believe this FA needs to be requested
> before the RMA is sent out, although I may be wrong.
>
> HTH
> DP
>
> -----Original Message-----
> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
> Guyler, Rik
> Sent: Thursday, July 14, 2005 11:26 AM
> To: cisco@groupstudy.com; 'ccielab@groupstudy.com'
> Subject: OT - Cat4k Sup3
>
> Has anybody had issues with the Cat4k Sup3 Engines causing CRC errors on
> gig links? We have many of these on our distribution closets and we
> seem to be replacing them currently at a rate of one every two weeks.
> We've swapped about a dozen so far and always after the swap the CRCs
> clear up so we know it's the Sups.
>
> Just curious if anybody else has had these issues as my Google searches
> haven't shown anything and Cisco isn't fessing up just yet... ;-)
>
> Thanks
>
> ---
> Rik Guyler
> Senior Network Engineer
> Network Technologies
> Premier Health Partners
> PH: (937) 278-6251 x2860
> FAX: (937) 276-7631
> PAGER: (937) 334-2711
> EMAIL: rguyler@shp-dayton.org
>
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