Client based gateway choice

[young]

Hi, I need some general info.

When employing a multi-wan router, is it possible for a client to simply select the gateway over which it desires to be routed ?
I assume it should at least be possible if the wan-interfaces have a secondary local ip, correct ?

The best option for me would be if a local networkhost could just set its default route as one of the routers outgoing interfaces, because I want to use dhcp to supply that routing information to the client.

Some explanations would be very welcome, thanks.

[cmb]

Not possible, the gateway is the internal-facing NIC. The only thing a gateway IP does is provide a MAC address to use for the destination of your off subnet bound traffic, which would be the same no matter how many IPs you put on an interface. If you dual homed the source machine, and put two internal NICs in the firewall, and could control routing from the source OS, you can do it that way. In most circumstances, such routing from the source OS will not be feasible.