You can also start from scratch.
To do it "live" look for your device in /etc/path_to_inst.
The interface will be either le0, hme0, glm0, or something along those lines. Then you can if you wish create entries in /etc/hosts and the hostname.Xe0 (the interface).
For example to make a 10/100 work type.
ifconfig hme0 plumb
ifconfig hme0 IPADDRESS NETMASK
ifconfig hme0 up
ifconfig -a should now show the working interface. Also see the man for route,resolv.conf,nsswitch.conf....
This will help you get up and running.