OpenBSD ipf.rules

I am trying to block netradio and napster traffic at my firewall. I have set rules such as ” block in on xl1 from any to any port = 7070 ” and several other ports and it`s not stopping the traffic into the LAN. I`m new to UNIX firewall admin and ANYhelp is appreciated. I have been pouring over the man pages with no resolve as yet.