half-duplex

[Bill Vermillion]

On Tue, Sep 05, 2006 at 12:18 , after knocking over a stack of dishes on
the heat sink Sam Wun
wondered out loud about:

> Hi,

> I am running a FreeBSD 5.4 stable as a network router.
> I don't know any reason why one of the ethernet ports becomes half-duplex.
> Here is its detail:

> em1: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
>        options=b<RXCSUM,TXCSUM,VLAN_MTU>
>        inet 60.1.2.3 netmask 0xfffffffc broadcast 220.233.99.39
>        ether 00:04:23:bc:3a:d1
>        media: Ethernet autoselect (10baseT/UTP <half-duplex>)
>        status: active
> em2: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
>        options=b<RXCSUM,TXCSUM,VLAN_MTU>
>        inet 10.1.10.1 netmask 0xffffff00 broadcast 10.1.10.255
>        ether 00:04:23:bc:3a:d2
>        media: Ethernet autoselect (1000baseTX <full-duplex>)
>        status: active

> This network card is a Quat Port Intel card. Is there any way
> I can "reset" it to full-duplex and 1000baseT without close
> down the network connection on em1? I know I can use following
> command to change it: ifconfig em1 media 100baseTX mediaopt
> full-duplex

Well 'em1' shows it is alos 10Mg second.  Autoselect >usually<
works well but there can be problems with some switches.   I am
assuming you are using a switch and not a hub - as that won't work
FDX.

You should be able to set the startup in the settings in your
rc.conf with the meidaopt argument.   man 4 em  shows that only
FDX is supported at high speeds - 1000mb/sec.   And you are getting
only 10mb. Is that what you want.  If you are connected to a switch
capable of 1000mbit, check the switch settings.   Cicso had release
notes and indicated 6 ways things will NOT work and one way it
will.

> but if this not work, it will close down the entire internet
> connection, which I try to avoid.

I don't know if using the 'mediopt' argument will shut down the
entire connection - but you probably are going to have to try.
If it works from the commnand line be sure to add it to the startup
script so it gets fixed on a reboot. 

It SHOULD work with auto-select unless you have switch and/or
cabling problems.

Bill
-- 
Bill Vermillion - bv @ wjv . com