I downloaded the iptables v1.2.11 and have got the directory structure in which I have the iptables binary in the source code .I then copy the binary iptables to another file system and so ./iptables -L .I get the output.But when I do SNAT i get the following :- $./iptables -t nat -A POSTROUTING -o eth0 -j SNAT --to 10.0.0.1 iptables v1.2.11: Unknown arg `--to' Try `iptables -h' or 'iptables --help' for more information. Please help me out .The directory also has binaries iptables-save and iptables-restore .Do I need to copy them too? I have even tried giving --to-source instead of --to. Does iptables v1.2.11 doesnt have support for SNAT ? i did iptables -h and couldnt find any --to or SNAT mention. have already compiled the kernel with options to enable inclusion of iptables modules .Also if i do ./iptables -t nat -L I get the nat table. This means that the nat module is already loaded i think. Please tell me the option intead of --to to enable SNAT.I am a naive user so please give a solution that would work.