[CentOS] TCP/IP Port Relay

Thu Apr 24 14:27:07 UTC 2008
Vahur Jõesalu <vahur at joesalu.com>

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)