Given: A computer running Linux (CentOS 5.x), one network card connected to LAN switch, a second one to cable modem via crossover cable. This computer acts as a router/firewall/traffic shaper for the local network.
Computer gets its public IP address from an ISP via DHCP. I know my ISP can supply 2 IP addresses to clients (when cable modem is connected directly to a hub, etc.). I would like to get 2 IP addresses on one computer that is connected to the ISP. It will simplify traffic segregation, NAT and shaping.
I know I can probably "fake" DHCP requests and bang together some scripts that will do this, but I wonder if somebody knows an easier and proper way.
Question: How can I make a Linux computer request two IP addresses via DHCP and assign both of them to one network card?