Switching between half-duplex and full duplex
freebsd at laws.ms
Mon Jun 4 10:35:16 UTC 2007
Rudolf Cejka wrote:
> Pang wrote (2007/06/03):
>> I have just installed FreeBSD and found that the nic em0 is set to
>> half-duplex only. Could anyone tell me how I can switch it to full-duplex?
>> em0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
>> inet 172.16.0.2 netmask 0xfffffffc broadcast 172.16.0.1
>> ether XX:XX:XX:XX:XX:XX
>> media: Ethernet autoselect (10baseT/UTP <half-duplex>)
>> status: active
> Hello, so I was right? ;o) I assume, that you have more capable device
> on the other side, atleast 100 Mb/s full-duplex. In that case, you should
> check, what connection type is "seen" on the other side (switches with
> management!). Then you can check auto-negotiation settings on the other
> side, try to change ethernet cable - it would be faulty and auto-neg would
> not work correctly, then look, which chipset do you have - the driver would
> not work with too new chips, I have here some ICH8 machines, which do work
> just 100 Mb/s instead of 1 Gb/s (I expect that -current should work now).
> PS: Another very good command is ifconfig -m em0, where you can see all
> allowed media/mediaopt combinations.
The auto-negotiation doesn't work properly. (it goes to half-duplex
automatically). But, it works when I switched it back full-duplex manually.
However, the switch doesn't seem to support 100baseTX or better.
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