I've noticed that both a router and individual devices on the network can be used to define a static IP address.

For example, my NAS can be set to have a static address (e.g. xxx.xxx.1.x), and the (DHCP on) router also can be set to reserve this address for that particular device, yet both settings appear to do the same job.

Is there any benefit in setting both devices (sort of doubling up), or just using one of them (and which one)?

R.