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

Larry Cook lcook at sybase.com
Wed Dec 8 11:38:01 EST 2004


Dan,

Thanks for your repsonse.

> 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.

I've tried three different cables directly connecting computer #2 and the 
router.  No difference.

> In some cheap 10/100 switches, the entire switch has to back down to 10,
> if any 10 device is attached. 

That does not appear to be the case with my Actiontec DSL-Modem/Router. 
Computer #1 has always been 10Mbs and computer #2 has always auto-sensed to 
100Mbs (according to it's indicator lights).

> I've seen 100 equipment fail to
> communicate because the link negotiation fails.

In those cases, did the status light indicate it has auto-sensed to 100Mbs?

> 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.

Okay.  That sounds like my problem.

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

Okay.  That could be the reason I get no communication.

> 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.

Yes, I agree.  Even if I find the underlying problem in the router, it's 
probably not "fixable".  I really just need to confirm the router is the 
problem.  Based on the responses so far, it appears that it could be having a 
100Mbs only 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.

Maybe mine is on it's way out too.  A ping of the router was showing 30-60% 
packet loss from a 100Mbs computer.  Now I have 100% packet loss from a 100Mbs 
computer.

Thanks,
Larry





More information about the gnhlug-discuss mailing list