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New Member

Cat4006 100Mb port vs. Cat2820 100Mb port...wierd problem


I made a 100 foot patch cable to run to a PC (standard straight-through) and it tests good with a cable tester. I connect the PC to a Cat4006 100MB port set for 100MB/full (the PC is forced as well). I get a link, but no data across. I set the port to 10/half and force the PC to 10/ works. If I connect the PC to a Cat2820's 100Mb port at 100Mb/full with the same works.

Does anyone know the difference between these switches/ports and why the speed/duplex is an issue? The entire cable run (100' patch plus the run to the wiring closet) is only about 150'. I think this should be close enough. The only thing I can see on the Cat4006 port while at 100/full are Rcv-Errs and FCS-Errs and a few Xmit-Errs.

I cannot figure out why the older switch can do this and the newer one cannot. Any thoughts? I've searched and searched and cannot find and relevent info. for this.



New Member

Re: Cat4006 100Mb port vs. Cat2820 100Mb port...wierd problem

looks like auto-negotiation issue between chipset on the NIC and switch. Please provide the nic card information. on a full duplex port you should not see any errors ideally.

New Member

Re: Cat4006 100Mb port vs. Cat2820 100Mb port...wierd problem

Thanks for the response. We have tested this on 3 different NICs:3Com, Intel, and Linksys. The speed/duplex have been forced at both the NIC and the switch. 100/full and 100/half do not work while 10/half works without trouble. Four different cables have been tested as well, with the same results. It's almost behaving like we are over the maximum distance for the cable (+ building wire, etc)..but, I swear the run is short enough.

I still cannot figure why 100/full on the Cat2820 works but the Cat4006 or Cat3524 will only work at 10/half. For now, I will force 10/half on it.

Thanks again.