I have a problem, I need to have to run a java program on a port < 1024. authbind and jsvc are no alternatives, it is simply decided not to use. But using ip6tables -t mangle -A PREROUTING -p udp --dport 546 -j TPROXY --on-port 8547 gives me ip6tables v1.4.7: unknown option `--on-port' What did I miss? uname -a Linux vieppetat12 2.6.32-71.el6.x86_64 #1 SMP Wed Sep 1 01:33:01 EDT 2010 x86_64 x86_64 x86_64 GNU/Linux