Automatic and manual assignment.
AUTOMATIC ASSIGNMENT
Most devices ask the network for an address when they connect.
The router assigns one from a range it manages.
WHY THAT IS USUAL
It requires no configuration and prevents conflicts.
MANUAL ASSIGNMENT
An address set on the device itself.
WHEN THAT IS USED
Servers Printers Equipment that must always be at the same address
THE RISK WITH MANUAL ASSIGNMENT
Assigning an address the router may also give to something else.
That produces a conflict, and both devices misbehave.
HOW TO AVOID IT
Set manual addresses outside the automatic range Or use a reservation, where the router always gives the same device the same address
RESERVATIONS
Usually the better approach.
Configured centrally, so nothing conflicts.
WHAT TO RECORD
Which devices have fixed addresses and what they are.
WHAT A CONFLICT LOOKS LIKE
Intermittent connectivity on two devices at once.
WHAT TO CHECK
The router's device list.
