Simple TCP proxy

Bopi · 07-24-2006, 12:19 PM

hello

i want to redirect all traffic i got on my internet interface to some site
so , if a internet user goes to my ip port 10000 , it redirects to some irc server.

anyone knows how to do this with iptables without instaling a tcp proxy ?

i dont want to redirect nothing to my local network so i guess using PREROUTING wont work

Matir · 07-24-2006, 12:47 PM

You're talking about going from Machine A to your Machine (B) to Machine C, with all 3 being on the internet? I suppose you could set up some sort of NAT rule for that, such as:

Code:

iptables -t nat -A PREROUTING -p tcp --dport 10000 -j DNAT --to-destination $SERVER:6667
iptables -t nat -A POSTROUTING -p tcp -d $SERVER --dport 6667 -j MASQUERADE

Bopi · 07-24-2006, 12:52 PM

yes , thats what i want, but your example does not work :|

Matir · 07-24-2006, 12:57 PM

What happens in this case?

Bopi · 07-24-2006, 01:06 PM

ùíù BitchX: Auto Response is set to - aaa
ùíù Connecting to port 10000 of server localhost [refnum 0]
ùíù Connection closed from localhost: Success
ùíù BitchX: Servers exhausted. Restarting.
ùíù Connecting to port 10000 of server localhost [refnum 0]
ùíù Connection closed from localhost: Success
ùíù BitchX: Servers exhausted. Restarting.
ùíù Connecting to port 10000 of server localhost [refnum 0]
ùíù Connection closed from localhost: Success
ùíù BitchX: Servers exhausted. Restarting.
ùíù Connecting to port 10000 of server localhost [refnum 0]
ùíù Connection closed from localhost: Success

BitchX is a irc client ... it keeps connecting , but fails

when i telnet port 10000 i got a connection refused

so i guess it wont do nothing

Matir · 07-24-2006, 01:28 PM

Do you have ip forwarding enabled? Are your policies set to accept?

Bopi · 07-24-2006, 01:32 PM

yes
ip forwarding enabled
echo "1" > /proc/sys/net/ipv4/ip_forward

all policys ACCEPT
Chain FORWARD (policy ACCEPT)

did u try this example at your box ? did it work ?

Matir · 07-24-2006, 01:35 PM

No, but my iptables rulesets are so complicated that sorting out behavior from this versus something else would be hard. Is there a reason you are averse to just using some sort of proxy or something? (i.e., a tool designed for the job)

Bopi · 07-24-2006, 01:40 PM

no , no problem , i just wonder why i need an external program , where iptables should do the job.
if i cant use iptables , then ill use one i got.

Matir · 07-24-2006, 01:47 PM

You may want to take a look at this site: http://www.linuxforums.org/forum/lin...ptables-2.html