[c-nsp] ATM CRC errors

[James Hamilton]

Bing!  Those are the missing crc errors!  I found a DSL pvc that is getting a
lot of crc's.  Using 'show atm vc detail' gave the additional info I needed
to find this one.  It surprised me that show interfaces | include CRC didn't
give the same info.  

Thanks to all who replied, it is *MUCH* appreciated.

On Wed, Oct 27, 2004 at 01:22:21PM -0600, Clinton Work wrote:
> 
> The CRCs are due to corrupted AAL5 frames coming on ATM PVCs. I agree that
> the
> cause is likely Quest dropping ATM cells inside their network due usage on
> the circuits
> exceeding the policed ATM rate. I have seen lots of CRCs before when unused
> PVCs
> werre left connected on the Telco side.
> 
> I would look for the PVCs getting a lot of CRCs and investigate them:
> 
> router>show atm vc detail  | inc Crc
> CrcErrors: 274, SarTimeOuts: 0, OverSizedSDUs: 0, LengthViolation: 0,
> CPIErrors: 0
> CrcErrors: 0, SarTimeOuts: 0, OverSizedSDUs: 0, LengthViolation: 0,
> CPIErrors: 0
> CrcErrors: 0, SarTimeOuts: 0, OverSizedSDUs: 0, LengthViolation: 0,
> CPIErrors: 0
> CrcErrors: 0, SarTimeOuts: 0, OverSizedSDUs: 0, LengthViolation: 0,
> CPIErrors: 0
> CrcErrors: 0, SarTimeOuts: 0, OverSizedSDUs: 0, LengthViolation: 0,
> CPIErrors: 0
> CrcErrors: 2161, SarTimeOuts: 0, OverSizedSDUs: 15, LengthViolation: 0,
> CPIErrors: 0   <--- Investigate
> CrcErrors: 0, SarTimeOuts: 0, OverSizedSDUs: 0, LengthViolation: 0,
> CPIErrors: 0
> CrcErrors: 2, SarTimeOuts: 0, OverSizedSDUs: 0, LengthViolation: 0,
> CPIErrors: 0
> CrcErrors: 0, SarTimeOuts: 0, OverSizedSDUs: 0, LengthViolation: 0,
> CPIErrors: 0
> CrcErrors: 24, SarTimeOuts: 0, OverSizedSDUs: 0, LengthViolation: 0,
> CPIErrors: 0
> CrcErrors: 0, SarTimeOuts: 0, OverSizedSDUs: 0, LengthViolation: 0,
> CPIErrors: 0
> CrcErrors: 0, SarTimeOuts: 0, OverSizedSDUs: 0, LengthViolation: 0,
> CPIErrors: 0
> CrcErrors: 0, SarTimeOuts: 0, OverSizedSDUs: 0, LengthViolation: 0,
> CPIErrors: 0
> CrcErrors: 0, SarTimeOuts: 0, OverSizedSDUs: 0, LengthViolation: 0,
> CPIErrors: 0
> CrcErrors: 9, SarTimeOuts: 0, OverSizedSDUs: 0, LengthViolation: 0,
> CPIErrors: 0
> CrcErrors: 0, SarTimeOuts: 0, OverSizedSDUs: 0, LengthViolation: 0,
> CPIErrors: 0
> CrcErrors: 0, SarTimeOuts: 0, OverSizedSDUs: 0, LengthViolation: 0,
> CPIErrors: 0
> CrcErrors: 0, SarTimeOuts: 0, OverSizedSDUs: 0, LengthViolation: 0,
> CPIErrors: 0

-- 

James Hamilton
Southwest Cyberport
http://www.swcp.com
505-232-7992