Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
Announcements

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. If you'd prefer to explore, try our test area to get started. And see here for current known issues.

New Member

Duplex mismatch causes WIC card to stop responding?

Hello. Our service provider 'accidentily' changed their LAN facing interface to auto-negotiate, but our switch is hard set to 100 full duplex. We didn't notice at first, except for a couple of missed pings when the change was made. Ou Internet access went down 4 hours after they made they change, and they couldn't figure out why. They rebooted the CE router, and everything was fine. This happened over 8 hours increments all weekend until they noticed the problem. They admitted that the when the WIC card see's a duplex mismatch for an extended period of time, it can become unresponsive. This actually caused all 4 ports on the WIC to become unresponsive.

Has anyone ever heard of this? It's a 3825 with a 4 port ethernet WIC. Traffic out the built-in port was working fine while the WIC ports were dead.

1 ACCEPTED SOLUTION

Accepted Solutions
Cisco Employee

Re: Duplex mismatch causes WIC card to stop responding?

We would need a little more information in order to fully answer this question.  Which WIC and IOS version are being used?  Do you have a show interface from the WIC when the "hang" is occuring?  It's possible that you are running into CSCsi03915 which reports a problem with the hiwc-4esw.  On that card, if a duplex mismatch is present the receive ring can become hung.  The only way to clear the problem is to reboot the router.


Tim

5 REPLIES
Bronze

Re: Duplex mismatch causes WIC card to stop responding?

Hello,

That 4 hours timer looks like the default ARP 4 hours timeout.

- Is the default ARP timer the one you are using?

- Do you have default route towards the CE using the exit-interface instead of a next-hop? ip route 0.0.0.0 0.0.0.0

Did you try setting your switchport to AUTO/AUTO to see if that solved the problem?

Regards.

Cisco Employee

Re: Duplex mismatch causes WIC card to stop responding?

We would need a little more information in order to fully answer this question.  Which WIC and IOS version are being used?  Do you have a show interface from the WIC when the "hang" is occuring?  It's possible that you are running into CSCsi03915 which reports a problem with the hiwc-4esw.  On that card, if a duplex mismatch is present the receive ring can become hung.  The only way to clear the problem is to reboot the router.


Tim

New Member

Re: Duplex mismatch causes WIC card to stop responding?

Thanks Tim, that really sounds like it could be the problem. Even though the article says 'several weeks', we were only several hours. I guess it depends on how much traffic the intefrcae see's. Thanks again.

New Member

Re: Duplex mismatch causes WIC card to stop responding?

The problem went away when the vendor changed their interface back to 100 full duplex, like it should have been. The only symptom I've ever experienced during a duplex mismatch is poor performance. This time, after between 4-6 hours, the WIC card simply stopped passing traffic. The WIC is an HWIC-4ESW, but I'm not sure what the IOS is, since we don't have access to it.

Cisco Employee

Re: Duplex mismatch causes WIC card to stop responding?

My guess is it was CSCsi03915, which effects the esw hwics.  The corrective action is to ensure there is no duplex mistmatch.

Tim

446
Views
0
Helpful
5
Replies