> iptables -m owner --socket-exist You may be looking for 'meta skuid'; you'll need the user ID that 'owns' a 'service'. You can `cat /etc/passwd` to find this information. 'meta skuid' will match a packet that is destined to or sourced from a socket that is owned by the user id that you specify. Try `su -l [username] -c "[executable path]"` to run a program as another user; if it does not do so already. Regards, sunny