Bridging with PF on OpenBSD
Wednesday, 28 Mar 2007
As part of tidying up “all those damn cables” and making it possible to walk around the study, I’ve been replacing the long 10+m cables I’ve used over recent years with shorter cross-over cables. Some of the newer NICs support automatic detection of the cable type & you can freely use normal cables instead of cross-over without issues. My soekris box unfortunately doesn’t support this with its 3 onboard NICs. Anyway, once I’ve got the cross-overs in place, the 2 workhorses, sendai & continuity, are wired directly into the soekris. Setting up a bridge was as easy as:
- reading the
brconfig
&bridgename.if
man pages - setting up
hostname.ath0
with the desired IP & subnet - configuring
hostname.sis0
&sis1
with “up” - and creating a simple
bridgename.bridge0
linking the three interfaces, and accepting only IP traffic across them
The next step, getting PF to send the traffic the right way, proved a little more troublesome….