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100MB network collisions


I have a 100mb hub with 2 machines connected to it. They're both on 100mb full-duplex - other one is 3Com Fast Etherlink and the other is an Intel EtherExpress.

The other machine is Win98SE and other is FreeBSD-4.3-STABLE. The problem is that whenever I try to transfer anything from one machine to other, it only flashes collision light and only 10k/sec data is transferred at max.

Any basical hints for this?

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1 Solution
You've got a link speed/mode negotiation problem, which is quite common with some of the lessor expensive hubs. With a 100Mbps hub you'll need to ensure that both systems are using 100Mbps half-duplex (hubs can't do full-duplex, only switches can do that AFAIK). On the FreeBSD box you can use ifconfig to set the port speed and mode and the driver tab on windows should have an option for setting speed/mode.
listening ..
acidiaAuthor Commented:
Thanks - that must be the reason (since it autodetects itself to full, and it works via cross-over _FAST_) - but how to set to half-duplex?

I've tried this :
ifconfig fxp0 media 100baseTX mediaopt half-duplex

but it says :
ifconfig SIOCSIFMEDIA: Device not configured

But it sure is configured ... :
ifconfig -au :
fxp: flags .....
inet netmask ... blah blah

It's there...

To set an Intel ExpressPro Nic to 100Mbps HDX use:

ifconfig fxp0 media 100baseTX

You'd only include a mediaopt argument if you were trying to set FDX on an interface that was running in HDX mode. Although there'd be no ereason to do so in your case, the manpage for that NIC (man fxp) will show you all of the permissible settings.
acidiaAuthor Commented:

Thanks - I'll put this as an answer since I think this is the problem. I can't seem to get those to go half-duplex, but they work via cross-over with full so that _has_ to be the problem.

I'll get a switch darnit :).

(btw I have another question about NIC's in BSD - I'll put it in the same group as this, and I think you could answer it also so please check :))

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