How to change the port from a specific IP address?

Question

Network routing

There is a device with ip address 1.1.1.1 from the external network sends a packet to my server with the address 2.2.2.2 Sender port
1000 receiver port 2000 whether in Windows or on the Keenetic Extra II router to do port forwarding according to the condition: If the packet is from 1.1.1.1 and the recipient's port is 2001, then change the recipient's port to 2000? ps I did not find it in the keenetic settings.

Answer 1

https://oldwiki.archive.openwrt.org/inbox/doc/ipta...
https://openwrt.org/toh/hwdata/zyxel/zyxel_keeneti...