Re: services behind NAT and firewall

From: Vincent Jaussaud (vincent.jaussaud_at_nospam.kelkoo.net)
Date: 04/29/05

  • Next message: azuredu: "Anybody interested in building an absolutely secure linux system?" 
    Date: Fri, 29 Apr 2005 11:35:27 +0200

    >> I'm not really certain of what you are asking here. It may be that
    >> OpenVPN will do what you want.
    >
    > No, OpenVPN can not do this :(
    >
    > COMPUTER_2 ==| firewall -- internet -- COMPUTER_1 -- Internet -- COMP_3
    >
    > and I want to connect from COMP_3 to COMPUTER_2 via COMPUTER_1
    >
    > COUMPUTER_2 is completely behind firewall and I want to make some kind
    > of all time connection from COUMPTER_2 to COUMPUTER_1 not from
    > COMPUTER_1 to COMPUTER_2 like VPN makes :)
    >

    If you have SSH access from COMPUTER_2 to the outside world (eg,
    COMPUTER_1), then you can do this with SSH port forwarding.

    eg; something like:

    on COMPUTER_2:

    ssh -R 3333:COMPUTER_2:22 username@COMPUTER_1

    This works by opening an SSH tunnel between COMPUTER_2 and COMPUTER_1. On
    COMPUTER_1 a local port is opened (here 3333), and every traffic coming
    into it will be forwarded across the SSH tunnel back to COMPUTER_2. From
    there, it is redirected to the local SSH server.

    In other words, once you've done that; on COMPUTER_1 you just have to do:
    ssh -p3333 username@localhost

    Further informations available in SSH man's pages.

    Note that you can use any ports you want instead of 3333 (above 1024;
    otherwise you'll have to be root), and you can use COMPUTER_3 instead of
    COMPUTER_1, as soon as you have direct access to it.

    Hope that helps. 

    -- 
Vincent Jaussaud, Kelkoo.com IT Architect
---
UNIX is many things to many people, but it's never been everything to
anybody.
  • Next message: azuredu: "Anybody interested in building an absolutely secure linux system?"

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