1. Computer problem? Tech Support Guy is completely free -- paid for by advertisers and donations. Click here to join today! If you're new to Tech Support Guy, we highly recommend that you visit our Guide for New Members.

Strange access problem! - please help!

Discussion in 'Networking' started by vJane3dr, Dec 9, 2011.

Thread Status:
Not open for further replies.
  1. vJane3dr

    vJane3dr Thread Starter

    Dec 9, 2011
    Hi There

    I have a strange access problem that I can not solve.
    I would REALLY appreciate if you could please help me solve this!!

    Basically, the network is a double NAT configuration as seen in the diagram below:

    (<-[DSL ROUTER]->LAN(<->(<-[ROUTER]->LAN(<->(

    [R1] => WAN<-[DSL ROUTER]->LAN
    [R2] => WAN<-[ROUTER]->LAN

    [IP X] =>
    [IP A] =>
    A & X are external IP's retrieved from ISP
    A( is an external IP that DSL R1 gets from my ISP for my network.
    X( is an IP that my wireless laptop gets from a near neighbour ISP ;)

    [C] =>
    [D] =>
    [E] => (Target NATed Server)
    B,C,D,E are all static NAT IP's in my local network.

    Both R1 & R2 routers are configured with port forwarding rule to allow access to NATed server 'E'.
    R1 forwards traffic to 'C' and R2 forwards traffic to 'E'

    The thing is that I CAN access server 'E' only by connecting from 'D' (pointing to
    (which is obvious as they both on the same subnet) or when I connect through my laptop from the external IP 'X'
    (pointing to

    Strangely however, I can *NOT* connect to server 'E' from points 'B'/'C' from my own lan!! :eek:
    (using either (or

    I can connect from 'B' to R2 router and enter it's config gui (R2 even shows server 'E' MAC address)
    (proves that my 'port forwarding is 100% OK), yet still I can only access 'E' from a pc on the same subnet ('D') or from a laptop on totally external IP 'X'

    How come it manages to connect from an outside ip, yet not from my own lan ?!?:eek: How can I solve this strange problem?

    Any help would be much appreciated!! (y)

As Seen On
As Seen On...

Welcome to Tech Support Guy!

Are you looking for the solution to your computer problem? Join our site today to ask your question. This site is completely free -- paid for by advertisers and donations.

If you're not already familiar with forums, watch our Welcome Guide to get started.

Join over 733,556 other people just like you!

Thread Status:
Not open for further replies.

Short URL to this thread: https://techguy.org/1030476

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice