When a private network uses a single public IP address, and each outgoing TCP packet uses a different port to allow for proper translation, what networking technology is in use?

A. PAT

B. NAT

C. NAPT

D. PNAT

A. PAT

Explanation:

IP addresses are logical addresses given to devices in network for routing purposes. It is just like a house in a street that needs an address.

There are two versions of IP address, namely;

- IP version 4

- IP version 6

IP version 6 (ipv6) : this is the latest of the two versions and have currently been adopted because of its almost infinite addresses as compared with the former version.

Two widely used types of ipv6 are global unicast and link-local address.

IP version 4: this is the oldest of the versions. It has five classes, but three are mainly used for networking they are;

Class A : 0 - 127 with a subnet mask of 255.0.0.0

Class B: 128-191 with subnet mask of 255.255.0.0

Class C: 192-223 with subnet mask of 255.255.255.0

Subnet mask are used to determine the network part and host part of the network. Eg;

192.168. 10. 3 with subnet 255.255.255.0

The portion of the subnet mask with "255" is the network portion while the "0" is the host portion.

There are two types of ipv4, they are private and public network address.

Private addresses are unroutable on the internet and range from;

10.0.0.0 - 10.255.255.255

172.16.0.0 - 172.31.255.255

192.168.0.0 - 192.168.255.255

Public addresses are routable on the internet.

When a company with a private network needs internet services, the router connected to modem is configured with a Network address translator "NAT" and with a port address translator "PAT".

PAT in the router is configured with a public address with a list of all the addresses in its private network, so workstations sending and requesting TCP packets to the internet is recorded in the PAT enable router and it IP address is changed to the configured public address and given appropriate port numbers for packets.

Answer: The answer is: PAT

Explanation:

PAT stands for Port Address Translation. It is a type and extension of NAT (Network Address Translation). The main difference between NAT and PAT is that in PAT technology multiple private IP addresses are translated or mapped into a single public IP using ports. It means that private addresses are mapped to public addresses by means of port numbers. The basic purpose of PAT is to preserve the IP addresses.

Example:

PAT is mostly used in a local area or home network. Lets take an example of a home network that is using an Internet. An IP address is allocated to its networking device i. e. router.

So when a computer wants access to the internet, the router allocates a port number to the client. A specific port number is allocated to each client to distinguish between them. This port number is added to the internal IP address of the computer. This gives unique address to each client.

What happens when another computer accesses the internet at the same time? It is allocated the same local IP address but with different port number. So both computers access internet at the same time but router distributes the data to the the specific client according to different port numbers added with the internal IP address of each client.