What
is Network Address Translation (NAT)?

NAT
is a method used to map private IP addresses to public IP addresses, allowing
devices on a private network to communicate with devices on the internet.

NAT
operates at the network layer of the OSI model, translating the source IP
address of a packet in the header to a different IP address before forwarding
it to its destination.

This
process enables private networks to use private IP addresses, which are not
routable on the public internet.

How
does NAT work?

When
a device on a private network initiates communication with a device on the
internet, the NAT device replaces the private IP address with a public IP
address assigned to it.

When
the response packet returns to the NAT device, it translates the destination IP
address from the public IP address back to the original private IP address and
forwards the packet to the intended device on the private network.

Types
of NAT:

There
are different types of NAT, each with its own specific use case. Let’s take a
look at some of the most common types:

Static
NAT:

In
static NAT, a single private IP address is mapped to a single public IP
address, and the mapping is permanent.

Static
NAT is used when a device on the internet needs to initiate communication with
a device on the private network.

Dynamic
NAT:

The
NAT device maintains a pool of public IP addresses that are assigned to devices
on the private network on a first-come, first-served basis.

Dynamic
NAT is typically used when a private network has a limited number of public IP
addresses available.

With
dynamic NAT, devices on the local network are assigned a public IP address from
a pool of available addresses when they access the Internet.

Once
the device disconnects from the Internet, the public IP address is returned to
the pool of available addresses.

Port
Address Translation – PAT

is a
type of NAT that maps multiple private IP addresses to a single public IP
address using different port numbers?

With
PAT, devices on a local network are assigned a unique port number when they
access the Internet. Incoming requests to the public IP address are then
translated to the correct private IP address based on the port number used.

Advantages
of NAT

Conserves
IP addresses: As mentioned earlier, NAT is an excellent way to conserve IP
addresses. By using a single public IP address, multiple devices on a local
network can access the Internet, reducing the number of public IP addresses
needed.

Increases
security: NAT adds an extra layer of security by hiding the private IP
addresses of devices on a local network from the Internet. This makes it harder
for hackers to target individual devices on the network.

Simplifies
network configuration: With NAT, network administrators can easily configure a
local network without having to worry about assigning unique public IP
addresses to each device on the network.