I had smilar problem.
Before you run arpspoof type: echo 1 > /proc/sys/net/ipv4/ip_forward
After you done the setting you need to assign an IP address within the same subnet to your Backtrack...
Type: Posts; User: woozny; Keyword(s):
Re: Does arpspoof kill the internet connection to the Host System in which BT5 runs
I had smilar problem.
Before you run arpspoof type: echo 1 > /proc/sys/net/ipv4/ip_forward
After you done the setting you need to assign an IP address within the same subnet to your Backtrack...