/etc/rc.conf 

ifconfig_igb0_alias0=”inet 192.168.30.10 netmask 255.255.255.0″
ifconfig_igb0_alias1=”inet 192.168.30.20 netmask 255.255.255.255″
ifconfig_igb0_alias2=”inet 192.168.30.30 netmask 255.255.255.255

ipv4_addrs_igb0=”xx.xx.xx.xx/26 192.168.30.81/24 192.168.30.82/24

ifconfig_rl0=”inet 192.168.1.2 netmask 255.255.255.0″
ifconfig_rl0_alias0=”inet 192.168.1.3 netmask 255.255.255.255″
ifconfig_rl0_alias1=”inet 192.168.1.4 netmask 255.255.255.255″