Our educational agency has been running on a 6x T1 Internet access with a class C IP range (256 addresses). Each of our Internet facing servers had a static external address (~10 total) and everything worked hunky dory.
The upper bodies that govern have decided to no longer pay for the Internet access… We’d also lose the IP addresses along the way. I thought this would be a good time to put the ASA-5510 that has been collecting dust on the shelf for 2 years into production. It would replace an ageing PIX 515. Now we have to scramble to find an ISP and if they can’t provide at least 3 or 4 IP addresses, I was wondering if everything could be routed through a single IP like shown in the attached diagram.
I'm in no way proficient with configuring a router from scratch, even less so when it comes to port forwarding. I know the 5510 can do NAT and PAT, but what about access to the 2 web servers? Can the 5510 distinguish the traffic meant for one or the other on port 80 and route accordingly? And I’m not sure of the video-conference unit… That might need to be on its own Internet access.
Any thoughts or suggestions would be welcome! I might add that cost is crucial since our budget has been slashed too...
As far i know the only way to map a single WAN IP to many LAN Hosts is trough NATP (port forwarding). You will need configure each Web server in two different ports (from the WAN side) and the router will know the destination host depending on the destination port.
You will need use IP NAT INSIDE SOURCE STATIC sentences for each forwarding, thus, a Web Server would be on port 80 but the another one must be on a different port (but same address since you will have only a public IP).
This forces the client to specify the port to acceding to the web server with the no standard WWW port number...or....
You can configure a unique Web server and depending on the URL this server redirects to server A or B, but this is server programming and to have 3 servers.
Apart of this i'm out of ideas, may be some one would help you more. Good luck.