SHOULD, yes. Although I didn't put my config in the original message, it's exactly what you put and what's in the example configuration. From npfctl show: map re0 dynamic any -> 76.169.240.26 pass family inet4 from 10.0.100.0/24Don't you want gif0 (or whatever) to be your external interface instead of re0 ?
Sorry - the context is in the original post. The gif tunnel is on a machine which is behind NAT, and the npf machine doing NAT isn't rewriting ipip.
John