On Sat, 27 Aug 2011 19:46:12 -0400
Sam Varshavchik <mrsam(a)courier-mta.com> wrote:
I forwarded a port, using system-config-firewall.
The destination machine, not surprisingly, shows the IP address of
the firewall as the source of the connection. The goal is obtaining
the connection's real source IP. However, on the firewall the
forwarded connection isn't reported anywhere by netstat or ss.
This is a DNAT forward? it should show the IP of whatever machine is
sending the request, not the firewall box in the middle.
After poking around, I found what I was looking for in
/proc/net/nf_conntrack. The forwarded connection was listed there,
showing the connection's real source IP.
But grepping through /proc/net/nf_conntrack seems to be rather
quaint. Neither netstat's nor ss's man page hint at any option that
would report on /proc/net/nf_conntrack in some user-friendly fashion.
Is there some other admin utility that does?
conntrack-tools has a 'conntrack' command line tool.
kevin