dynamic IP

my pc is connected to a wireless router. my internet incoming connection is connected to the router.
I connected my arduino mega 2560 with ethernet shield to the router by wire.
Then I did IPCONFIG of my PC and get the ip address of my PC and the ip address of my router(gateway).
Accordingly I assigned suitable ip to arduino. It works and communicates with my CITECT scada.

Now I want that if the ip of arduino is assigned by router ( is it dynamic ?) and if is it changing? If the ip of router is assigned by ISP and if it is changing? But in scada i used the ip that i assigned to arduino ; means it is not changed? But i have idea that router assigns local ip to arduino and pc ? if the ip of router changes after some time then i have to change the gateway for arduino else it w’nt work.

finally tell me if the ip of router and arduino is changing or not?

thanks thanks thanks

Your router's localnet IP will not change, so your gateway IP setting will not change. The public IP on the router will change, but that will affect you only if you plan on accessing the Arduino/router from the internet.

If you use DHCP to assign the network settings to the Arduino, its localnet IP could change.