Re: Forcing a particular IP address out to an interface

nick4soup_at_yahoo.com.au
Date: 10/13/05

  • Next message: GS: "Every time my Linux PC gets new Ip address, I can't access remotely, how can I access?/" 
    Date: 12 Oct 2005 15:44:08 -0700

    Floyd L. Davidson wrote:

    > It never gets anywhere near the route table though. If the IP
    > address is assigned to an interface on the host, it goes to the
    > lo device regardless of what is in the route table.

    As they would say in New Zealand, BUGGER.

    Next approach: pretend that the ppp0 interface on the 'left' box has IP
    addresses:
       192.168.3.xx, and use iptables to mangle the destination address of
    the packet somewhere along its route.

      1. Therefore on left, I ping 192.168.3.23.
      2. It will route out to 'right', via eth0
      3. when right receives the packet, it will forward to the ppp0
    connection, courtesy of its default route (we also have masquerading
    here, changes source addr to 192.168.1.10)
      4. in 'left', I will have to use iptables to mangle the incoming
    packet to alter the destination address to 192.168.1.23

    It requires I use something like (please excuse syntax):
      iptables -t nat -A PREROUTING -i ppp+ --dst 192.168.3.23 -j DNAT
    --todestination-addr 192.168.1.23

    I already tried mangling the outgoing packet on left using
      iptables -t nat -A OUTPUT --dst 192.168.3.23 -j DNAT
    --todestination-addr 192.168.1.23
    but I ran into the same razor.

    Nick Bishop, email replies ignored.
    -----
    Position vacant: suicide bomber.
    Previous experience essential.
    -oOo-

  • Next message: GS: "Every time my Linux PC gets new Ip address, I can't access remotely, how can I access?/"

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