>
> kstratton> I just went through some painful debug session(s) with my
> kstratton> ISP. For some reason, after forcing 10 base T half duplex
> kstratton> through my windows box directly to my modem (I do not
> kstratton> expect ISPs to support linux),everything suddenly worked
> kstratton> (after reconnection and re-enabling of course).
>
> Can you give more details on the cable modem box you're using and the
> PC as well? Such as what network card in the PC you are using?
>
> kstratton> How often does this kind of thing happen? I have seen this
> kstratton> kind of thing before only once before, and I was using an
> kstratton> old hub that only supported 10 base T, not a home router
> kstratton> that is supposed to autodetect the port type. I remember
> kstratton> that the modem only supports 10 base T, but I am not 100%
> kstratton> certain.
>
> Sun and Cisco were notirious for having problems figuring our
> autonegotiation on the Sun hme (Happy Meal Ethernet) cards. They'd
> end up 100Full on one side and 100 Half Duplex on the other. It would
> work, just very slowly...
>
> kstratton> Does anybody have an explanation of what most likely
> kstratton> happened? Do not hesitate to skimp on technical details or
> kstratton> references if is convenient. I desperately want to
> kstratton> understand what happened. --
>
> Something didn't autonegotiate properly. Did you try powering off
> both devices and then powering them on starting with the cable box?
>
> Also, alot of Cable Companies lock the cable box to the first MAC
> (ethernet hardware address) they see coming over the link. So if you
> boot up with a PC, and then try to move to something else like a NAT
> box or a linux box acting as a NAT box, things can go wonky.
>
> Usually a hard reset of the Cablemodem will do the trick, but
> sometimes you need to contact the ISP and ask them to reset it for
> you.
>
> In your case, it really sounds like a problem with Autonegotiation.
> Some devices just don't do a good job, esp older equipment from before
> the Gigabit ethernet stage.
>
> Just to expand on Frank's email, the people who designed the Gigiabit
> Ethernet standard over Copper (802.xxx I can't remember) saw all the
> problems with the 100/10 devices and autonegotiation and explicity
> made AutoNeg part of the spec in a very well detailed way, so that
> these problems won't happen again. As a matter of fact, Gigabit ports
> are much smarter and don't require crossover cables either, you can
> just plug them into back to back, they figure out what's going on
> automatically and adjust.
>
> The joys of big ASICs!
>
> John
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