using iptables to change a destination port but keep the ip the same.
- by Scott Chamberlain
I am playing around with transparent proxies, The current way I am doing things is the program makes a request to a computer on port 80, I use
iptables -t nat -A OUTPUT -p tcp --destination-port 80 -j REDIRECT --to-port 1234
to redirect to my proxy that I am playing with. the proxy will send out a request to port 81 (as all outbound port 80 are being fed back in to the proxy so I want to do something like
iptables -t nat -A OUTPUT -p tcp --destination-port 81 -j DNAT --to-destination xxxx:80
The problem lies with the xxxx part. How do I change the destination port without changing changing the destination ip? Or am I doing this setup completely wrong, I am learning after all and constructive criticism is definitely appreciated.