Rookie needs help...

Discussion in 'General Discussion' started by Rubens Sayegh, Jul 23, 2007.

  1. Rubens Sayegh

    Rubens Sayegh LI Guru Member

    Hi All!

    I´m a rookie when dealing with routing tables and Routers/Gateways terminology, and I need a little help...

    I have a broadband connection to the Internet and my ISP gives me a dynamic IP address. So, my Windows 2K is configured to "Obtain IP Address Automatically".

    Whenever I connect to the ISP I am given a new IP addr. So far, so good.
    I also have a NetFileServer running on my machine, and due to this changing IP address, I use NO-IP DUC to convert the Server´s "URL" to the actual IP address in use. In this way, users from the "outside" can reach my machine by it´s URL, instead of the IP address, and Upload/Download files, via http (port 80). Again, so far, so good...

    Yesterday I installed a LinkSys WRT54G Router, to make two machines reach the Internet. It is configured as "Gateway".

    Now, the IP address that my ISP gives me will be used by the Router and this one will provide my machines with new IP addresses, now LAN-based. With this, my NetFile Server is now with an internal IP addr., and not able to be broadcast to the outside world...

    What I need is to know how to create a routing table (is that it?) to make the outside world able to reach my server again, something like...
    IPS --> Dynam. IP addr. <--> Router <--> my Server

    I´ve already checked the Router´s configuration and could not make it work that way. I know there´s a way to create some sort of internal routing so whenever the outside user types my Server´s URL, it will be directed to my Router, and this one will re-direct to my Server, enabling http traffic (inbound and outbound) via port 80.

    Any help would be greatly appreciated.
    Thanking in advance,
    Rubens Sayegh
  2. t4thfavor

    t4thfavor Network Guru Member

    What you need is port forwarding. It is what will enable people to connect to your isp facing ip address and get your lan file server.

    From what you said it looks like you are sharing files off of a webserver? If so all you need to do is open port 80 on the wrt54g and point it to the ip of your internal server.

    So it will act as a sort of proxy, and people will never know the difference.
  3. HennieM

    HennieM Network Guru Member

    Also now tell your WRT54G, not your computer, to register your ISP obtained IP address with dyndns or something similar - I assume that is what this NO-IP DUC is.
  4. t4thfavor

    t4thfavor Network Guru Member

    Oops I forgot to say that. I believe you will need 3rd party firmware in order to use the service since they have their own client.

    I use and I had to install openwrt, and then install the no-ip client before I got it to work. Now its set it and forget it.
  5. Rubens Sayegh

    Rubens Sayegh LI Guru Member

    Thank you guys for the prompt answers.
    I believe that´s what I have to do, but am still a bit confused about "who" is the Default Gateway, and other stuff...

    As far as I know, I have to configure the WRT54G creating an entry in the "Routing Table" and specify...
    Destination LAN IP - The IP obtained from the Router, to the Server (in this case, my machine -
    Subnet mask -
    Default Gateway - Here´s the problem... When I issue "ipconfig /all" in my W2K machine, I have as "IP Address" and "Default Gateway" - Is this the one? Or should I use the "external" IP address provided by my ISP to the Router (
    Interface - LAN & Wireless - I assume this is the correct option - as opposed to "WAN (Internet)" - due to the fact that the Server itself is located "inside" my environment (from the outside, after passing the Router, everything in on a LAN, correct?).

    Another doubt... HennieM wrote "Also now tell your WRT54G, not your computer, to register your ISP obtained IP address with dyndns or something similar - I assume that is what this NO-IP DUC is."...

    The DUC is a tool that stays on in my computer and periodically connects to the NO-IP site and "informs" them that the IP address given to my machine is such-and-such... So, whenever someone types "http://<name_of_my_domain>" in the browser´s address field, the connection is redirected to the NO-IP site and, by means of a table, NO-IP "informs" that the correct address to reach is that "such-and-such" address. So, whenever my dynamic IP address is changed, DUC performs an update in NO-IP´s tables and the user can still reach my "home" by the name, without worrying with IP "numbers"...

    But, how do I register this dynamic address in the Router?

    Sorry to bother you with this type of question, but as I said, I am still a "rookie" with this terminology.

    Again I thank you for the advices.
  6. HennieM

    HennieM Network Guru Member

    Rubens, here some short pointers that will hopefully get you on your way fishing...

    Your router now has the external (internet side) IP address, and your PC has an internal (192.168.x.x) address. PC talks to internal side of router, so PC's defaut gateway must be, and router's external side talks to internet.

    See and/or These are the ones I coud find quickly, but there may be more informative sites out there.

    I would also suggest that you register with dyndns or another dynamic DNS service supported by your router instead of no-ip.

    For an internet -> your PC connection, you connect to the external (internet side) of your router, and then tell your router to port forward to your PC.
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