[TriLUG] Linux as a bridge?

[gregbrown at mindspring.com]

Can a linux box with two ethernet interfaces act as a bridge at layer 2?  I know I can route between two interfaces but I'd like to use two interfaces as a bridge where I can apply my firewall rules.  Any ideas?

Currently the only layer 2 firewall I'm aware of is the Lucent Brick, but I'd sure like to aviod spending the $1500.00 (plus SMS server) and use a linux box.

Greg