port mapping

shoaib · 10-09-2004, 04:15 AM

Hi , i have question how i can map one port to another in linux.

Like i have a port open 9091 on linux and i wanted to make redirect all requests to port 7891 on the same linux machine.

is it possible ...
please let me know thanks.
Shoaib.

Demonbane · 10-09-2004, 04:59 AM

Yeah, something like

Code:

iptables -t nat -A PREROUTING -p tcp --dport 9091 -j REDIRECT --to-port 7891

keep in mind that this is only a redirection, so clients in fact are still communicating to port 7891(though it appears to them as port 9091), if you block access to port 7891 things won't work.

shoaib · 10-09-2004, 06:31 AM

I did this command like this

iptables -t nat -A PREROUTING -i eth0 -p tcp --dport 10000 -j REDIRECT --to-port 7860

it worked fine but when i try to get the list of iptalbes it is showing nothing and the worst part is that i cant remove this rule .
I tried to flush it and delete it but no effect. it is redirecting from 10000 to 7860 still. ...

Is it a bug or iam doing some thing wrong....................................

shoaib · 10-09-2004, 07:40 AM

I tried every thing ... i dont know what i am missing. The listing of iptables displays empty tables but the rule is working fine.
cant remove it thats the big problem. is it a bug or what..

Demonbane · 10-09-2004, 01:51 PM

The "nat" table is a built-in table which doesn't show if you just do iptables -L.

to show it:
iptables -t nat -L

to flush it:
iptables -t nat -F