Everyone, As I understand it, OSF has been merged with the Kernel since 2.6.before-my-kernel-version. Yet when I do something like this: iptables -I INPUT -j ACCEPT -p tcp -m osf --genre Linux --log 0 --ttl 2 and I get an error like: iptables: No chain/target/match by that name iptables -L Shows no rules because I did an iptables -F at one point. ALSO, the following command: cat /proc/net/ip_tables_matches Does not show "osf" on the list. A google doesn't seem to help. I've also installed iptables-devel in hopes I'd be able to load the osf module. Sadly I haven't been able to get that to work. Centos 6.4 minimal Any guidance?