There are two kinds of bridge:

1. standard, boring, old bridge that stores and forwards all packets in
both directions - traditionally used to extend an Ethernet beyond its 1km
maximum cable length. No one makes 'em like this any more.

2. a "learning bridge" also known as a "switch" - it pays attention to
which Ethernet devices are on which wire, and does not forward local
conversations (packets between two stations on the same wire). Still must
forward all broadcasts, multicasts, and non-local packets.

It should be easy to make bridge type #1. Be careful not to fiddle the
Ethernet frame (like, by substituting your own Ethernet address as the
source of packets you forward) because bridges are supposed to be totally
invisible, aside from the delay they add.

If anyone tries to do a learning bridge or switch daemon for NetBSD, let me
know? I have an application for it...

	Erik <fair@clock.org>