[nsp] Automated tool for catching duplex mismatches on switc h ports?

[Andrew Fort]

Temkin, David [29/04/03 18:58 -0400]:
> Only catches it if you've got a duplex mismatch between CDP devices, or in
> some cases if the switch is set to auto but the device is hard codeed and
> you get late collisions... But if it's the other way around (the switch is
> hardcoded and the device isn't) then FCS and Alignment errors don't get
> logged.  
> 
> Thanks tho.

Well, another way to look for it is that if the port is running enough errors
you'll get this type of log message (from a 2900XL/3500XL and 6500
Native IOS iirc);

76849: Apr 30 00:58:33: %LINK-4-ERROR: FastEthernet0/14 is experiencing errors

One thing to beware of with the CDP duplex mismatch warnings, which is that
because CDP messages will be transparently forwarded through some non-cisco
devices (i.e., between VLANs on Alteon switches in some softwares), the
message may not be talking about the directly connected port, but rather
some other device behind it.  Yet another good reason to disable CDP on
customer facing ports.

-afort