Possible to use two ethernet ports at once?

There's no way your internet connection is faster then one 1Gb ethernet port, unless you're very, very, *very* lucky.

If you insisted, here's the most brain-damaged way to do it. For instance, this is your "behind the router" interface:

en0: 192.168.0.69

"Internet" interface:

en1: 1.2.3.3

Your nat router is 192.168.0.1, your ISP gateway is 1.2.3.1. (I'm assuming you bought a block of static IPs from your ISP, of course, and the router's consuming one.) Set your routing table like so:

default 192.168.0.1
192.168.0.0/24 en0
(whatever the netmask of your ISP connection is) en1

Add firewall rules like so:

ipfw add 1000 fwd 1.2.3.1 tcp from any to any dst-port 80
ipfw add 1001 fwd 1.2.3.1 tcp from any to any dst-port 443

Now your http/https traffic is skipping the router and going to the internet directly, while everything else uses the default gateway, which of course is the internal address.

What this accomplishes I dunno, but there you go.

--Peace

The grungy ipfw-level tools limit choosing gateways for traffic to either service type (aka, port) or destination IP. Peer to peer involves essentially random IPs, and usually involves multiple (and semi-random) ports. So doing this with bittorrent-type programs is sort of out. If you're exchanging data with (downloading from) a single (or well defined manageable list) of IPs then you can do it. (Get the list of IPs, put them in an ipfw table, and use a command syntax similar to above except referencing the table as the destination address and leaving out the port numbers.)

You're probably better off doing your pirating on a separate computer. ;^)

--Peace