[NCLUG] configuring dual IP addresses, forwarding one to the other network card.

[Andrew Gilmore]

On May 27, 2014 12:00 PM, <nclug-request at lists.nclug.org> wrote:
> Date: Tue, 27 May 2014 11:27:20 -0600
> From: John Gilmore <j.arthur.gilmore at gmail.com>
> To: Northern Colorado Linux Users Group <nclug at lists.nclug.org>
> Subject: [NCLUG] configuring dual IP addresses, forwarding one to the
>         other network card.
> Message-ID:
>         <CAD9ZuxBJc9i1w-Z5qM=xFuO2mdhRCiMzdHkDWpg0F=
KBAFi8pw at mail.gmail.com>
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>
> I want to give my computer two IP addresses on eth1, and forward one
> of them transparently out eth0, in order to monitor network traffic to
> my printer.
>
> Script/suggestions? I figure one of you guys knows how to do this
> right of the top of your head.

I just stick an old 10mbit hub I have laying around between the printer and
the router, and tcpdump the traffic from the hub.

Otherwise, you can bridge the traffic or as the other guy said, just
reassign the IP and wireshark it.

Andrew