How to assign Static IP for a MAC address in Router

here we can see how to configure a static IP address to a MAC address. Below is a setup for Beetel WiFi router 

In this case, added the IP 192.168.1.6 and associated it with the MAC address 00:22:5F:63:9A:BF. 

Once a new entry is added, it needs to be saved, In the beetel case, the SAVE button is at the bottom of the page

One might think the add option is missing easily. 

Now once the mapping is added, the router can be restarted and find that the association is not changed. 

this should not change unless the mapping is removed.  

references:

http://lifehacker.com/5822605/how-to-set-up-dhcp-reservations-so-you-never-have-to-check-an-ip-address-again