Dead easy (se você souber como)
sudo ifdown eth0
gksudo gedit /etc/network/interfaces
Adicione o seguinte ao final:
auto eth0
allow-hotplug eth0
iface eth0 inet loopback
iface eth0 inet static
address 192.168.200.200
netmask 255.255.255.0
executar:
sudo ifup eth0
Presto: um loopback eth0 no software!
ping 192.168.200.200
PING 192.168.200.200 (192.168.200.200) 56(84) bytes of data.
64 bytes from 192.168.200.200: icmp_seq=1 ttl=64 time=0.073 ms
64 bytes from 192.168.200.200: icmp_seq=2 ttl=64 time=0.042 ms
64 bytes from 192.168.200.200: icmp_seq=3 ttl=64 time=0.069 ms
64 bytes from 192.168.200.200: icmp_seq=4 ttl=64 time=0.044 ms
^C
--- 192.168.200.200 ping statistics ---
4 packets transmitted, 4 received, 0% packet loss, time 2997ms
rtt min/avg/max/mdev = 0.042/0.057/0.073/0.014 ms