Re: Reverse IP NAT to secondary IP address

From: Nils Vogels (nivo+sender+8eb026_at_yuckfou.org)
Date: 10/26/03

  • Next message: _at_babolo.ru: "Re: Reverse IP NAT to secondary IP address" 
    Date: Sun, 26 Oct 2003 03:34:58 +0100
To: freebsd-net@freebsd.org

    "."@babolo.ru wrote:

    >configure port with SNMP-server as 192.168.0.17/30 for example
    >instead 192.168.2.1/24, and
    >sysctl net.link.ether.inet.proxyall=1
    >
    >and configure SNMP-server as 192.168.0.18/24
    >
    >If you can change mask of SNMP-server, you can
    >use 192.168.0/24 and 192.168.1/24 on gateway
    >and 192.168.0/25 on SNMP-server.
    >
    >No NAT is needed.
    >
    >
    I just tried this, but unfortunately, the same thing happens as with
    ipfilter:

    The primary address of the interface ed0 on the gateway (the public
    adress) is used to forward the arp request.

    Taken from a dump on the gateay, when attempting telnet:

    Incoming on rl0:
    03:35:05.867883 192.168.0.2.1511 > 192.168.2.2.23: S
    1377718084:1377718084(0) win 57344 <mss 1460> (DF) [tos 0x10]

    Outgoing on ed0:
    03:35:05.868333 195.0.0.1.15009 > 192.168.2.2.23: S
    1377718084:1377718084(0) win 57344 <mss 1460> (DF) [tos 0x10]

    Since 195.0.0.1 (obviously obfuscated) does not fall within the subnet
    the 192.168.2.2 box is on, there will never be a reply from the
    192.168.2.2 box.

    ARP proxying goes fine, on the WWW box, I can see the proxied reply
    coming from my gateway for the 192.168.1.1 address .....

    Can anyone tell me, how I can make the box use the secondary address
    (alias) automatically for forwarding the telnet session?
    Could it be that since the gateway is running many-to-one NAT as well,
    this is conflicting ?

    Greetings,

    Nils.

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  • Next message: _at_babolo.ru: "Re: Reverse IP NAT to secondary IP address"

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