I have a CISCO 2811 router with 2 Gigabit Ethernet ports. One port is used by a firewall, and the other port is for the LAN. Currently, I have a flat network that I want to chnage by putting the servers in my data center on a different subnet. Since I don't have spare port on the router, is it possible to create subinterface (on the ethernet port connected to LAN) and how? What is the best practice?
Thank you much.