Looking for odd software NAT for windows xp - TCP-IP

This is a discussion on Looking for odd software NAT for windows xp - TCP-IP ; Given three Ethernet devices: PC A (Win XP) PC B (Win XP) Cable Modem (actually ethernet bridge) All connected to an Ethernet Switch PC A uses DHCP to get public IP address via Cable Modem Internet connection is working perfectly ...

+ Reply to Thread
Results 1 to 2 of 2

Thread: Looking for odd software NAT for windows xp

  1. Looking for odd software NAT for windows xp

    Given three Ethernet devices:

    PC A (Win XP)
    PC B (Win XP)
    Cable Modem (actually ethernet bridge)

    All connected to an Ethernet Switch

    PC A uses DHCP to get public IP address via Cable Modem

    Internet connection is working perfectly

    the problem is the ISP will only allocate one IP address per cable
    modem

    so when PC B sends DHCP request it is refused

    all the software NAT solutions expect two interfaces

    but my "public" and "private" networks are both on PC A Ethernet
    Interface but on different subnets

    (using registry hack PC A and B both support DHCP *and* static
    192.168.1/24 addresses)

    what I need is a software NAT on PC A that will accept IP traffic from
    192.168.1 subnet and NAT out to public network

    I could just buy a cable router and junk the cable modem

    but am now curious if this is possible


  2. Re: Looking for odd software NAT for windows xp

    On 9 Sep, 21:30, John Rivers wrote:
    > Given three Ethernet devices:
    >
    > PC A (Win XP)
    > PC B (Win XP)
    > Cable Modem (actually ethernet bridge)
    >
    > All connected to an Ethernet Switch
    >
    > PC A uses DHCP to get public IP address via Cable Modem
    >
    > Internet connection is working perfectly
    >
    > the problem is the ISP will only allocate one IP address per cable
    > modem
    >
    > so when PC B sends DHCP request it is refused
    >
    > all the software NAT solutions expect two interfaces
    >
    > but my "public" and "private" networks are both on PC A Ethernet
    > Interface but on different subnets
    >
    > (using registry hack PC A and B both support DHCP *and* static
    > 192.168.1/24 addresses)
    >
    > what I need is a software NAT on PC A that will accept IP traffic from
    > 192.168.1 subnet and NAT out to public network
    >
    > I could just buy a cable router and junk the cable modem
    >
    > but am now curious if this is possible


    You need to configure your PC B to have PC A as a gateway for ALL
    addresses - then configure your PC A to act like a router. But, in
    this configuration I do not think that firewall function of this PC A
    router will be useful. Because your cable modem (and everybody
    outside) will still see your PC B and will be able to access it if you
    are not careful in configuring firewall on PC B.


+ Reply to Thread