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Re: Problems with the 3Com 3c905B NIC

>>>>> "RG" == Ron Golan <rgolan@coalabs.com> writes:
    RG> I'm jumping into this thread in the middle. Please excuse me if
    RG> this has already been pointed out. Cable modem systems typically
    RG> only allow packets from one particular MAC address. In your case
    RG> it would be the one of the supplied NIC, 00:80:C6:EE:A2:E3. When
    RG> you swapped the NIC, the MAC address changed to
    RG> 00:01:02:ca:90:fb. The fact the that the LEDs are blinking on
    RG> the cable modem means that the 3Com NIC is sending packets to
    RG> it. I think the packets are being denied by the the cable
    RG> companies router or gateway and thats why you don't get any
    RG> response back to the originating machine.

That's exactly what I thought as well. Except that the stupid
Rogers@Home techs tell me that is not true and that I am doing sth else
wrong. They just gave me their standard answer: reinstall the networking
and TCP/IP components.

One tech I spoke to actually said that it might be possible for their
routers to be caching the MAC address of my NIC in its (router's) ARP
table. I have already tried powering off my cable modem for > 3 hours to
see if that would allow me connect using a different NIC, but that
didn't work.

As per the tech's suggestion, I stayed offline for 6 hours which he said
would be enough time for the router to flush its ARP table cache. But
that hasn't worked. I can only connect to Rogers@Home with the one
Sohoware NDC 10/100 NIC.

    RG> A simpler test for the 3Com NIC would be to use a crossover
    RG> cable between it and another known working NIC in another
    RG> computer. If this test should show the 3Com NIC to be working,
    RG> then you could request your cable company to change the allowed
    RG> MAC address to that one.

Well, I ditched the 3Com NICs for D-Link NICs (530 TX+s). I had the same
problems with the D-Link NICs, but did verify that the two D-Link NICs
are working fine by using a crossover cable b/w them.

Salman Ahmed
ssahmed AT pathcom DOT com

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