induced
asked on
Netopia DSL Modem/Router Static IPs vs. Lan IPs
I have a Netopia Cayman 5700 series DSL modem/router. My ISP is SBC. I have 1 wan IP and 5 assigned LAN IPs. I was told that these 5 assigned IPs were accessible publicly. My question is, why would they give me 5 static LAN IPs? As far as I knew, the LAN IPs were not accessible publicly because of that NAT sharing the WAN IP. Why would they give me 5 LAN IPs that I can just make up using the whole range from 2-255? It's like they want me to pay for more LAN IPs if I have more than 5 computers, when I don't even need to use their assigned LAN IPs in the first place. I have tried setting one of the computers to one of these Static LAN IPs and then pinging it from a public computer through another connection. The static IP doesn't respond, as though it never got the ping, and therefore, isn't public at all. Maybe someone else knows how SBC works and why they operate the way they do. I asked why I am not just assigned another WAN IP that I can bind to a specific local IP, and they just said "that's not how we do it anymore." SBC employees who I talked to were complete BASTARDS. I know you guys will answer this question without a problem. Thanks for the help.
ASKER
I tried using the Netopia Router mapping one of those IP's they gave me to a specific local IP, but it told me the IP I used (which they gave me), was an invalid IP. . . Has anyone with SBC and Static IP service run into this issue?
ASKER CERTIFIED SOLUTION
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
ASKER
Thanks
No worries, mate ;-)
Often the ISP will configure the router so that 5 LAN hosts will be accessible from public internet, but this doesn't mean that they assign public addresses. They do it by using a principle called PAT (Port-Address-translation)
If this is the case for you, the following setup should apply (only as example, - actual port-to-IP mapping should be in your documentation):
Anyone from public calling http://[your WAN address] will be routed to your internal PC with an internal IP of e.g. 192.168.1.3.
In this way you can setup your own: mail, www, ftp, dns, telnet, etc..