~$ cat /etc/network/interfaces
# interfaces(5) file used by ifup(

and ifdown(

auto lo
iface lo inet loopback
~$ ifconfig -a
eth0 Link encap:Ethernet HWaddr 00:21:85:05:d4:18
inet6 addr: fe80::221:85ff:fe05:d418/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:502 errors:0 dropped:0 overruns:0 frame:0
TX packets:545 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:212605 (212.6 KB) TX bytes:82069 (82.0 KB)
lo Link encap:Локальная петля (Loopback)
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:65536 Metric:1
RX packets:279 errors:0 dropped:0 overruns:0 frame:0
TX packets:279 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:22650 (22.6 KB) TX bytes:22650 (22.6 KB)
ppp0 Link encap:Протокол PPP (Point-to-Point Protocol)
inet addr:100.68.74.237 P-t-P:100.68.0.1 Mask:255.255.255.255
UP POINTOPOINT RUNNING NOARP MULTICAST MTU:1492 Metric:1
RX packets:475 errors:0 dropped:0 overruns:0 frame:0
TX packets:493 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:3
RX bytes:200342 (200.3 KB) TX bytes:63295 (63.2 KB)
~$