sis driver

[Cordula's Web]

> sis0: <NatSemi DP83815 10/100BaseTX> port 0xc4
> 00-0xc4ff mem 0xe0120000-0xe0120fff irq 12 at device 11.0 on pci0
> sis0: Ethernet address: 00:40:f4:60:ad:47
> miibus0: <MII bus> on sis0
> ukphy0: <Generic IEEE 802.3u media interface> on miibus0
> ukphy0:  10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, auto

The sis(4) driver had some issues with autoselect in the past.
Just try ifconfig's 'media' option, or update your kernel.

-- 
Cordula's Web. http://www.cordula.ws/