Redirect requests to my external IP/port to a different external IP/port?

Question

Is it possible to redirect connections to a specific IP/port to an external IP/port?

Example:

• Server A has the external IP xxx.xxx.xxx.xxx
• Server B has the external IP yyy.yyy.yyy.yyy
• User sends a request to server A on port 2106, I want to redirect it to server B at port 2106.

Solution

Problem solved:

sysctl net.ipv4.ip_forward=1
iptables -t nat -A PREROUTING -p tcp --dport port -j DNAT --to-destination ip:port
iptables -t nat -A POSTROUTING -j MASQUERADE

Where ip and port are the target server I want to redirect the current server port to.

Comments

[singpolyma]

This does not work for me. Specifically, that last line causes all traffic from my machine to itself to appear to come from outside, and similar problems.

[Jezor]

@Prix wouldn't that redirect all traffic to a specified port (2106) to yyy.yyy.yyy.yyy:port? What if I'd like to redirect traffic that goes only to xxx.xxx.xxx.xxx:port?