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New Member

What are FCS errors?

I have a 6509 with a WS-X6348-RJ-45 blade installed and on one port I am receiving a count in the "FCS-Err" column. There are no other errors. What are FCS errors?

5 REPLIES
Anonymous
N/A

Re: What are FCS errors?

Frame Check Sequence errors indicating that frames of data are being corrupted during transmission; this number should be a very small percentage of the total data traffic. Check the cable and the connected device.

New Member

Re: What are FCS errors?

If not down to a physical problem, then these can be caused by duplex mismatches between switch and the end device. Try manually setting the speed/duplex at both ends.

Seach cisco.com for "duplex mismatch" as there is a document available that explains this topic in detail

Cisco Employee

Re: What are FCS errors?

New Member

Re: What are FCS errors?

If not down to a physical problem, then these can be caused by duplex mismatches between switch and the end device. Try manually setting the speed/duplex at both ends.

Seach cisco.com for "duplex mismatch" as there is a document available that explains this topic in detail.

Are you getting slow performance/lost packets etc?? If so, then this will be down to the duplex mismatch.

New Member

Re: What are FCS errors?

FCS means Frame Check Sequence Errors and ...yes it can be duplex, speed

PT

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