In message <Pine.LNX.email@example.com> you write: > Short Answer: Packet data payload, ports, protocols. Ah. OK, you want a generic packet classifier which hooks into PRE_ROUTING (maybe LOCAL_OUT) and sets the mark. There's a classifier in the sched/ code, or you could use iptables as a base. Yes, you have to write it. 8-) Rusty. -- Hacking time.