NAT for Windows 2000 Server

Posted on 2006-03-23
Last Modified: 2013-11-30
I need resources and instructions for speeding up and configuring NAT for Windows 2000 Servers (website URLs preferred).

My problem is that I have 2 Internet connections and 2 routers.  I would like all incoming and outgoing SMTP traffic to go through a DSL connection; any other Internet Trafiic I want to go through a cable connection.  
Question by:npinfotech
    LVL 2

    Accepted Solution

    Hrm. I had a long post about how this wasn't possible without high-end filtering routers, but then something simple occured to me.

    If your SMTP is server-based (I mean you have an exchange server or whatever), then you can have the LAN and email server on the same network, but configure the mail server to use the 2nd internet connection (change the gateway and DNS it uses) and leave the rest of the network with the gateway set to the cable connection.

    If it isn't server-based (ie you use externally hosted email) then you'd need some expensive packet-filtering router between the LAN and the 2 connections, and have it filter traffic to one or the other based on packet headers.

    LVL 8

    Author Comment

    I route all gateways to a hardware firewall.  I think I may be able to configure the DNS of the mail server (which I have onsite) to use the DSL router, and configure the DNS that all clients use to go through the cable modem.

    I'll give it a shot.
    LVL 2

    Expert Comment

    Ah but using the DNS of one ISP, and having the gateway set to the other firewall will still make the traffic flow out through the first, and may actually cause problems, since many ISPs don't allow DNS queries from outside their network. You'll have to change the gateway I think.

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