Configuring network interface to listen only

[omegahalo-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Chris O'Connell)]

Hi Everyone,

I'm in the midst of migrating my SNORT installation over to a new server.  I
have a second NIC in the server that I'm going to plug into a port on my
switch which is mirrored to the uplink.  I need to configure this interface
to listen only, which means it gets no IP address.

I've configured this once before but kind of fumbled my way through it.  Can
anyone tell me what I need to do to configure an ethernet port to listen
only?

Thanks!

Chris