Configure the machine with a static IP address in /etc/rc.conf
In /etc/rc.local put the following type entries. ifconfig fxp0 192.78.4.55 netmask 255.255.255.255 alias ifconfig fxp0 192.78.4.56 netmask 255.255.255.255 alias ifconfig fxp0 media 100baseTX mediaopt full-duplex
