Windows – Does Default Gateway IP = Router IP

you can get a DrayTek 2950 router, supports multiple public IP addresses amongst other features. supports vpn tunnels (200) without purchasing extra licenses.

http://www.draytek.co.uk/products/vigor2950.html

You can search for a draytek dealer in your area.

Draytek will do all port forwarding, you can connect multiple WAN connections, can run them in either failover or load-balance mode, you can assign WAN IP Aliases (Public IP Addresses). You can even assign Public static IP to your servers and input the correct subnet and subnet mask in your router so it routes your public IP subnet too.

Hope that helps

A router needs to be sized for the load it is expected to handle. In our campus network, the big 6500's in the middle of the networks are orders of magnitude more powerful than the router that links us to our ISPs. This is because most of our generated traffic is internal oriented. That border device is shoveling around 500Mb/s, but the backplane on our core routers are handling well above that, and multiple VLANs as well.

Concurrency isn't a terribly big issues so long as the router is just routing packets. Even small routers can handle terribly high concurrency rates. Internal tables are kept for routing, which networks are available on what interfaces, and the ARP table, which hardware devices are visible to each interface. The big 6500's at our core have ARP-tables around 10K in size, where the ISP border router is probably closer to 30 entries.

Once a router starts having to maintain connection-state for either firewall or NAT duties, that greatly increases the CPU and memory requirements for a router. Small home-routers doing FW/NAT can only go so far before the NAT table gets exhausted. Behind our border router is a Cisco ASA firewall, and that DOES have to handle all of our incoming and outgoing connections in memory. I don't know what the average connection-count is, but we're able to consistently do around 450Mb/s with simple web-browsing traffic so it has to be very high.

If we had a second firewall surrounding our server subnets specifically, that firewall wouldn't have to be as beefy as the one at our gateway. The Gateway firewall has to monitor all traffic to the server subnets as well as traffic leaving from all of the internal LANs with end-user generated outgoing connections.