Hi Timo,
Try 'ifconfig eth0 172.16.254.80 netmask 255.255.255.240 up' or, after you already issued those commands, a simple 'ifconfig eth0 up'.
Yup did that
then: route ass default gw 172.16.254.1
I get: Network is unreachable
I can ping 172.16.254.1 from my Mac though.
-Jason