ipfw: Add support for NAT on different routing tables.
This patch adds an option "fib FIB_NO" to the "ipfw nat" command which lets you set the routing table on the NAT instance to FIB FIB_NO. We also make libalias and ipfw tag packets on a routing table if specified.
This can be useful in say, using two connections via one router.
Submitted by: Neel Chauhan <neel AT neelc DOT org>