what is the Dynamic nat or nat overload
Dynamic NAT or NAT overload
Dynamic NAT
Mapping: A many-to-many mapping where an internal device is assigned a unique public IP address from a pool for its internet session.
Requirement: Needs a pool of public IP addresses, one for each internal device that needs to be online simultaneously.
Use case: Useful when there are multiple public IP addresses available, but you don't need a fixed mapping for each device, such as for clients connecting to a server.
NAT overload (Port Address Translation - PAT)
Mapping: A many-to-one mapping where multiple private IP addresses are mapped to a single public IP address.
Requirement: Only requires one public IP address, making it extremely efficient for conserving IP addresses.
How it works: The router uses different source port numbers to keep track of the different internal devices and their connections. The router's NAT table stores the unique combinations of private IP and port number, allowing it to correctly route incoming traffic to the right internal device.
Use case: Ideal for environments with a limited number of public IP addresses, such as residential and small to large enterprise networks.