Hello, Good Day. Anyone could help me out with this error using the string argument. [root@ja Desktop]# iptables -o eth0 -A FORWARD -p tcp -m string --string "X-Kazaa-Username:" -j REJECT --reject-with tcp-reset iptables v1.3.4: STRING match: You must specify `--algo' Try `iptables -h' or 'iptables --help' for more information. [root@ja Desktop]# However, if I specify the --algo if have this error [root@ja Desktop]# iptables -o eth0 -A FORWARD -p tcp -m string --string --algo "X-Kazaa-Username:" -j REJECT --reject-with tcp-reset Bad argument `X-Kazaa-Username:' Try `iptables -h' or 'iptables --help' for more information. [root@ja Desktop]# Thanks in advance __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com