Results 1 to 4 of 4

Thread: Dual WAN Ubuntu Router

  1. #1
    Join Date
    Sep 2008
    Ubuntu 9.04 Jaunty Jackalope

    Dual WAN Ubuntu Router


    I'm thinking of setting up a Ubuntu Server box as a router.
    I have about 10 machines on my LAN which host various things (http, ftp and other servers) and I'm connected to two different ISPs.
    From what I've figured I need a machine with 3 NICs and a Gigabit Switch (I already have this one). Now on the Ubuntu box I would have one card for each ISP and one for my LAN.
    The problem I'm afraid I will encounter is that the servers (http,ftp etc.) won't be accessible from both ISPs because the machines that host the servers have only one gateway.
    I would need to forward the same ports (80,21) to the same machine. I suppose that my Ubuntu box would simply forward the requests from both outside interfaces (from each ISP) to the correct machines inside but the responses from the machines would go out in the Internet through only one interface (which is the default gateway on the machine from the LAN).
    If I were to use SNAT...would the packets follow the right path (my guess is yes but I haven't used it before so I'm not sure) Would I need two local interfaces for this (one for each WAN connection)? . Anyway using SNAT would mean the servers would think that all the connections are coming from the same IP (the local IP of my Ubuntu Box which is also the default gateway) - so this would render useless any logs or "visits" page.
    How do DualWan routers achieve this?


    Best wishes,
    Before posting be sure to use the Forum search function

  2. #2
    Join Date
    Apr 2009

    Re: Dual WAN Ubuntu Router

    Hey there.

    I am actually running a dual WAN ubuntu server right now. It is working awesome.

    The reason why I went for a homebuilt solution over the others out there (pfsense, mono/smooth wall) was for the customization. Since it is a true linux box, and not someone else's hacked up version, I could do whatever I want with it.

    Even though you are using SNAT, your client PCs won't see the connections coming from the ubuntu box, rather, it will see them as from the real internet. I proved this by doing a tcpdump on a box inside the LAN, and initiating a connection from the Internet, and watched the srcip, and it was the public IP of the host initiating the source.

    If you want me to, I can try and share what I did to get this box up and running....I made scripts for everything, so it should be fairly simple. After I set it up the first time, I was able to get dual WAN working within 5 minutes after a fresh install.

    Let me know!


  3. #3
    Join Date
    Jul 2007

    Re: Dual WAN Ubuntu Router

    I have found this thread looking for help on setting up an ubuntu box as dual WAN router.
    Dear jbarbieri, will you please tell how you accomplished said task.
    Thanks in advance,

  4. #4
    Join Date
    Apr 2009

    Re: Dual WAN Ubuntu Router

Tags for this Thread


Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts