Edit IPTABLES to redirect to a different IP

[Tim J]

I have come across an issue where I have a slave employee time clock that is coded with an IP address to communicate with master time clock at a different location. The IP address for where the master clock is does not have a static IP address. I have no way of changing the IP on the slave clock without deleting all the data on it that I need.

I think I can change the iptables in my Asus router by going in and executing the below command but nothing happening and when I look at the logs it is still trying to communicate to the old IP and not the one I want it to.

iptables -t nat -A OUTPUT -p tcp -d (IP Clock wants to communicate with) --dport 10923 -j DNAT --to-destination (NEWIP):10923

Any thoughts?

Thanks Tim

 

[ColinTaylor]

Try using the PREROUTING chain.

iptables -t nat -A PREROUTING -p tcp -d (IP Clock wants to communicate with) --dport 10923 -j DNAT --to-destination (NEWIP):10923