Query all interface information :
ifconfig -a lo0: flags=2001000849 mtu 8232 index 1 inet 127.0.0.1 netmask ff000000 e1000g0: flags=1000843 mtu 1500 index 2 inet 192.168.1.1 netmask ffffff00 broadcast 192.168.1.255 ether 0:c:29:21:12:f5
Plumb all interfaces
bash-3.2# ifconfig -a plumb ifconfig: SIOCSLIFNAME for ip: e1000g0: already exists bash-3.2#
Query again and you will see newly added network interface
bash-3.2# ifconfig -a
lo0: flags=2001000849 mtu 8232 index 1
inet 127.0.0.1 netmask ff000000
e1000g0: flags=1000843 mtu 1500 index 2
inet 192.168.1.1 netmask ffffff00 broadcast 192.168.1.255
ether 0:c:29:21:12:f5
e1000g1: flags=1000842 mtu 1500 index 3
inet 0.0.0.0 netmask 0
ether 0:c:29:21:12:ff
bash-3.2#
Configure new interface
bash-3.2# ifconfig e1000g1 10.10.10.1 netmask 255.255.255.0 up
bash-3.2# ifconfig -a
lo0: flags=2001000849 mtu 8232 index 1
inet 127.0.0.1 netmask ff000000
e1000g0: flags=1000843 mtu 1500 index 2
inet 192.168.1.1 netmask ffffff00 broadcast 192.168.1.255
ether 0:c:29:21:12:f5
e1000g1: flags=1000843 mtu 1500 index 3
inet 10.10.10.1 netmask ffffff00 broadcast 10.10.10.255
ether 0:c:29:21:12:ff
Make changes permanent
bash-3.2# ls -ltr /etc/hostname*
-rw-r–r– 1 root root 9 Jan 31 06:12 /etc/hostname.e1000g0
Create file for new interface e1000g1
bash-3.2# gedit /etc/hostname.e1000g1
bash-3.2# ls -ltr /etc/hostname*
-rw-r–r– 1 root root 9 Jan 31 06:12 /etc/hostname.e1000g0
-rw-r–r– 1 root root 14 Jan 31 06:46 /etc/hostname.e1000g1
reboot machine
bash-3.2# reboot