Can only the 100Mbs part of a 10/100Mbs router fail?

Dan Jenkins dan at rastech.com
Wed Dec 8 09:17:01 EST 2004


>> I'm having a network problem that appears to be that the 10/100Mbs
>>  ports on my router are no longer working at 100Mbs, but are
>> working at 10Mbs. Is it possible that just the 100Mbs part could
>> fail?

I've seen this problem a few times.

In one case it was a bad patch cable. The cable worked at 10Mbps but not
100Mbps. I didn't try to determine why. Just replaced it.

In some cheap 10/100 switches, the entire switch has to back down to 10,
if any 10 device is attached. I've seen 100 equipment fail to
communicate because the link negotiation fails.

I've had network connections negotiate one speed and fail to communicate
on it. I've replaced either the network card or the switch to solve.

As someone mentioned, the connection between the 10 and 100 networks in
the switch may have failed.

None of the ones I've seen were worth the effort of identifying the
cause since all were with real cheap equipment. Swapping out was more
economical than finding the underlying problem.

But, yes, I've seen the 100Mbps part of a switch fail, but 10Mbps still
work. I've used the failing switch elsewhere in our in-house network
just for 10Mbps equipment. It would not successfully connect to 100Mbps
devices. Eventually it just died completely.

-- 
Dan Jenkins (dan at rastech.com)
Rastech Inc., Bedford, NH, USA --- 1-603-206-9951
*** Technical Support for over a Quarter Century



More information about the gnhlug-discuss mailing list