When you specify a reserved IP address for a computer on the LAN, that computer always receives the same IP address each time it accesses  the router's DHCP server. Assign reserved IP addresses to computers or servers that require permanent IP settings. 

To reserve an IP address:

1. Launch a web browser from a computer or mobile device that is connected to your router’s network.
2. Enter http://www.routerlogin.net.
   A login window displays.
3. Enter the router user name and password.
   The user name is admin and the default password is password. The user name and password are case-sensitive.
   The BASIC Home page displays.
4. Select ADVANCED > Setup > LAN Setup.
5. In the Address Reservation section of the page, click the Add button.
6. In the IP Address field, enter the IP address to assign to the computer or server.
7. Choose an IP address from the router’s LAN subnet, such as 192.168.1.x.
8. Enter the MAC address of the computer or server.
   Note: If the computer is already on your network, you can copy its MAC address from the Attached Devices page and paste it into the  field.
9. Click the Apply button.
   The reserved address is entered into the table.

The reserved address is not assigned until the next time the computer contacts the router’s DHCP server. Reboot the computer, or access its IP configuration and force a DHCP release and renew.