Sharing Internet Modem via Lan on Backtrack (Linux)

To get internet form other computer, first we set our ip, gateway and DNS in our computer.

The text which blue color is our computer (computer A). And the red color is the other computer which connect to the internet (computer I).

1. First, in computer I we look for network information about ppp0.

# ifconfig ppp0
ppp0 Link encap:Point-to-Point Protocol
inet addr:10.77.221.111 P-t-P:192.168.11.10 Mask:255.255.255.255
UP POINTOPOINT RUNNING NOARP MULTICAST MTU:1500 Metric:1
RX packets:21275 errors:4 dropped:0 overruns:0 frame:0
TX packets:21823 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:3
RX bytes:24204058 (24.2 MB) TX bytes:2716284 (2.7 MB)

The conclusion, ip ppp0 computer I is 10.77.221.111.