RRAS / NAT / IP Routing Help

Discussion in 'MCSE' started by Guest, Feb 21, 2004.

  1. Guest

    Guest Guest

    Ok so here's where Im having trouble

    My network (at home) is setup like s

    gateway=192.168.1.

    xp box 192.168.1.x [|] multihomed RRAS server=192.168.1.x (public interface

    RRAS Private interface=172.16.x.x [|] Server2 = 172.16.x.

    everything on 192.168.1.x is connected to my gateway, which goes to my internet connecto

    the 172.16.x.x subnet between the 2 servers is connected via crossover.

    everything is fine as far as internet browsing goes. from all PCs I can get to the forums :

    I can connect via unc from 172.163.x.x subnet to any pc. but my xp box cannot see the 172.16.x.x subne

    If I ping to 172.16.x.x it gets to the 192.168.1.x interface on the RRAS server, but never hits the 172.16.x.x interface (have confirmed this with network monitor).

    So far I have checked my routing tables, and everything looks to be in order. bsically 172.16.x.x to 192.168.1.x works fine, but not the other way around. Ip routing an demand dial is enabled in RRAS (as welkl as remote access).

    I have also attempted modifying HKLM\system\currentcontrolset\services\tcpip\parameters\ key=ipenablerouter to a value of one, but this did not change anything. I have also tried adding a static route to the 172.16.x.x subnet on the RRAS server (on any and all interfaces) but still no luck. also tried disabling remote access just to make sure that this was not interfering. THere are no IPfilters enabled at all on the RRAS server

    oh yeah, and also...

    with Remote access enabled, if I connect via VPN to the public RRAS interface, I can ping back and forth just fine (Remote connection is assigned an Ip on 172.16.x.x subnet) from that point, I can do whatever I want both ways...

    So basically, it appears to me that somewhere between the "public" interface and "private' interface the packets are dropped, but only from the 192.168.1.x > 172.16.x.x direction

    Any ideas? Please help! im stuck. :

    *more coffee

    thanks for any suggestions!
     
    Guest, Feb 21, 2004
    #1
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  2. Guest

    Mark Scott Guest

    is there a connection from the xp box to 172.17?

    cannot see the 172.16.x.x subnet
    server, but never hits the 172.16.x.x interface (have confirmed this with
    network monitor).
    order. bsically 172.16.x.x to 192.168.1.x works fine, but not the other way
    around. Ip routing an demand dial is enabled in RRAS (as welkl as remote
    access).
    HKLM\system\currentcontrolset\services\tcpip\parameters\ key=ipenablerouter
    to a value of one, but this did not change anything. I have also tried
    adding a static route to the 172.16.x.x subnet on the RRAS server (on any
    and all interfaces) but still no luck. also tried disabling remote access
    just to make sure that this was not interfering. THere are no IPfilters
    enabled at all on the RRAS server.
    interface, I can ping back and forth just fine (Remote connection is
    assigned an Ip on 172.16.x.x subnet) from that point, I can do whatever I
    want both ways...
    interface and "private' interface the packets are dropped, but only from the
    192.168.1.x > 172.16.x.x direction.
     
    Mark Scott, Feb 21, 2004
    #2
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  3. Guest

    Guest Guest

    First off, thanks for the reply! :

    No, there is no direct connection from the Xp box to 172.16.x.x subnet.

    I got to fiddling with it again today, and if I remove NAT, I can ping across just fine, but as soon as I reinstall NAT, everything gets dropped at the public interface. Is this one of those "by design" issues. Can I not initiate the ping (or other traffic) from outside the public interface to the private subnet? I know that you can create special port mapopings (IE 21 goes to internal host x.x.x.x) in order to direct certain types of traffic addressed to the public interface to a specific private host, but if I have the private address defined in the incoming packet, and the server has a valid route to that subnet, shoudn't it route the packet? Am I wrong in assuming this?
     
    Guest, Feb 21, 2004
    #3
  4. Guest

    Guest Guest

    Found a workaround by creating a resevation in the address pool for my private network host. Cant connect directly to the private address from the pubilc network, but I can connect via the public address I used for the reservation, which is mapped to the private host. :)
     
    Guest, Feb 22, 2004
    #4
  5. Guest

    Jesse PH Guest

    nat uses private ip.
    i just dont know if you can nat on both private ip.
    check routing tables. test connectivity.

    Jesse PH

    across just fine, but as soon as I reinstall NAT, everything gets dropped at
    the public interface. Is this one of those "by design" issues. Can I not
    initiate the ping (or other traffic) from outside the public interface to
    the private subnet? I know that you can create special port mapopings (IE 21
    goes to internal host x.x.x.x) in order to direct certain types of traffic
    addressed to the public interface to a specific private host, but if I have
    the private address defined in the incoming packet, and the server has a
    valid route to that subnet, shoudn't it route the packet? Am I wrong in
    assuming this?
     
    Jesse PH, Feb 23, 2004
    #5
  6. Guest

    Jesse PH Guest

    ip mappings. you can map public ip to private ip.
    access your private ip thru the mapped public ip.

    Jesse PH

    private network host. Cant connect directly to the private address from the
    pubilc network, but I can connect via the public address I used for the
    reservation, which is mapped to the private host. :)
     
    Jesse PH, Feb 23, 2004
    #6
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