Input Errors and CRC Counters

[telcomwork]

Can someone explain whether the counters "Input Error" and "CRC" when doing a "SHOW INTERFACE" command on a Cisco Router are errors taken from the WAN side or LAN side?

My main question is that if I am receiving many errors on both of these counters is it a carrier problem or could it be the switch the routers connected to?

Thank you for your time.

 

[vlan52]

If you are looking at any FastEthernet´s interface counters for example, anything that shows up as errors, frames, CRC's belong to that particular interface and its connection with the device on the other side of course.

Particularly if you perform a show int over a ..., let's say Serial interface, and you find errors, CRC's, etc...check woth your carrier to perform a couple of tests + loops perhaps.

Make sure you compare the number of errors with the numbers of packets in/out the interface too.

Hope this helps,

 

[rburke]

I've done tech support for dedicated lines before and if you are getting lots of CRC/Input Errors, then you will need to try to replace some cords. (aka the line from the SmartJack to the router usually) But hten again it depends on your provider and the level of their support.

burke

 

[CCIEWANNABE]

Input Errors can includes runts, giants, no buffer, CRC, frame, overrun, and ignored counts. Check ecaspsulation matches, connectors and ARP tables. See if there is any unnecessary ARP broadcasts.

CRC usually indicates noise or transmission problems on the LAN interface or the LAN bus itself. A high number of CRCs is usually the result of collisions or a station transmitting bad data. Again check ARP tales.
Route once; switch many

 

[telcomwork]

Thanks to all for the help! It was a bad cable.