Nat address

Posted on 2008-11-10
Last Modified: 2012-05-05
Whats the purpose of having multiple Nat address.
Question by:New_Bridge_Multimedia
    1 Comment
    LVL 58

    Accepted Solution


    I assume by 'NAT address' you mean external static IP address, right?

    The main point of having multiple external static IPs is not so much for connecting out to the Internet, but when you need to forward ports through the firewall into the network. You may need more than one external IP so you can forward the same port to various machines internally. You cannot forward the same port to different PCs on the same static IP, so you'd need two static IPs to achieve this. For example, say I want to open the terminal services port 3389 to two servers; I'd need two external static IPs, so I can then configure my firewall to listen on 3389 on the first IP and forward to Server1, and do the same on the second IP, but forward to Server 2.

    Another use in the reverse direction (talking out to the Internet) is to enable you to have different internal systems show as using different external IP addresses. A common example would be a mail server; you can use a different external static IP on that server, so that all the DNS (PTR and MX etc.) records can be configured to match, but it won't impact on the rest of the network.


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