[CentOS] TCP/IP Port Relay

Thu Apr 24 14:42:22 UTC 2008
Frank M. Ramaekers <FRamaekers at ailife.com>

Yes, I was thinking along those lines, but I thought I'd ask.   THANKS!

Frank M. Ramaekers Jr.
Systems Programmer                   MCP, MCP+I, MCSE & RHCE
American Income Life Insurance Co.   Phone: (254)761-6649
1200 Wooded Acres Dr.                Fax:   (254)741-5777
Waco, Texas  76710
-----Original Message-----
From: centos-bounces at centos.org [mailto:centos-bounces at centos.org] On Behalf Of Vahur Jõesalu
Sent: Thursday, April 24, 2008 9:27 AM
To: CentOS mailing list
Subject: Re: [CentOS] TCP/IP Port Relay

hmm, if I understood you correctly, then this should work just fine (on 
linux firewall):

/sbin/iptables -t nat -I PREROUTING -p tcp --dport 23 -j DNAT \
--to telnetserverip:port-number
/sbin/iptables -I FORWARD -i external_interface -o internal_interface \ 
-p tcp -d telnetserverip --dport portnumberontelnetserver -j ACCEPT

after a reboot or firewall service restart it's gone again.


Frank M. Ramaekers wrote:
> What is the best way to temporarily setup a port relay.  I'm trying to
> diagnose a problem with Cisco's latest VPN client and need to determine
> if the problem is port number related.
> e.g.  VPN client---------23-(Linux box to relay port)-------xx-(Telnet
> server)
> (Keep in mind this is temporary and for debugging purposes)
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