Matthew,

I get le0 detected hen the kernel boots,

> le0 at sbus0 slot 0 offset 0xc00000 level 5: address 08:00:20:0f:5e:de
> le0: 8 receive buffers, 2 transmit buffers

except mine says address ff:ff:ff:ff:ff:ff

ifconfig le0 gives
le0: flags=8822<BROADCAST,NOTRALIERS,SIMPLEX,MULTICAST>mtu 1500
	media: Ethernet 10base5
	inet 0.0.0.0 netmask 0x0

and if I try and assign an IP...
ifconfig le0 203.33.30.210 netmask 0xffffff00
this changes to
le0: flags=8863<UP,BROADCAST,NOTRALIERS,RUNNING,SIMPLEX,MULTICAST>mtu 1500
	media: Ethernet 10base5
	status: active
	inet 203.33.30.210 netmask 0xffffff00 broadcast 203.33.30.255

I also should mention that I get the following messages on a different
machine when I try to configure this one...
arp: ether address is broadcast for IP address 203.33.30.210!

I should also mention that the network port works a treat under SunOS, I
managed to download and write the boot disk I am using from under SunOS and
if I try and boot back into SunOS, I can configure the network using
ifconfig.

Thanks again
craig