Some people change their public, external IP address to avoid online bans or to bypass country location restrictions that some sites impose on video content.
Changing the IP address of a client computer, phone, or router is useful when:
An invalid address is accidentally configured, such as a static IP address in the wrong numeric range.
A malfunctioning router provides bad addresses, such as an address that is used by another computer on the network.
Know more @ technician workstation
Installing a new router and re-configuring a home network to use its default IP address range.
To change the router's IP address, log in to the router as an administrator. From the control panel, change the IP address to whatever you like. However, this IP address is usually changed when there's a problem with it. The default IP address should suffice for most situations.
Another way to change a static IP address is to first find out where the address is being assigned from. If the router is holding or reserving that address, make the change from the router; the steps are different for every brand and model.