The knowledge about Network Address Translation is essential for a person to pass CCNA 100-101 exam as it is one of the major sections in the course outline.

Network Address Translation:

Point of Demarcation:
Commonly it is termed as POD. It is physical point in a network where the public network from Internet Service Provider or ISP ends and the local network of a client begin; usually it is the point where the cable from the internet provider company enters the building of client.


In the above figure the block shows the Customer-Provided Equipment (CPE) area and ISP is an Internet service provider. In the CPE area, the management of network is the responsibility of customer.

Understanding of DHCP:

It stands for Dynamic Host Configuration Protocol. It is a client-server model and is responsible for the allocation and configuration of IP addresses.


In the above figure, there is a DHCP server and its clients. The DHCP server has a pool of IP addresses ranges from to This server is responsible for the allocation of IP addresses to its clients. The clients will request the server for the allocation of IP addresses and in return, the server will allot unique IP addresses to the clients. The DHCP servers minimize the time required for this task.

DHCP IP Allocation Mechanisms:

  • Automatic Allocation: In this case a permanent IP address is allocated to the client.
  • Dynamic Allocation: The IP address is assigned to the client for the limited period of time.
  • Manual Allocation: An IP address is assigned to the client manually by the network administrator.

Types and Classes of IP Addresses:
There are two types of IP addresses i.e. Public and Private. These are classified into different classes as shown the tables belowIP Addresses

What is NAT?

It stands for Network Address Translation. It is the process of translating an IP address used in one network to the IP address known by another one. One network is termed as Inside Network and other one is called as Outside Network.

Types of NAT:

  • Static NAT: It is a type of network translation in which one-to-one address mapping is done. It is used when a device in private network needs to be accessible from internet.
  • Dynamic NAT: In dynamic NAT many-to-many address mapping is done.
  • PAT: It stands for Port Address Translation. Many-to-one address mapping is involved in it.

The different types of addresses in NAT are as follows

  • Inside Local: It represents the address of the host on the internal network e.g.
  • Inside Global: It represents he mapped address which other people on the internet would see.
  • Outside Global: It represents the address of the remote internet-based host.

From the above discussion we conclude that the Network Address Translation is plays an important role when we have to remap on IP address space into another. As we know that the internet is expanding day by day and in this scenario, NAT helps us to expand our network in a secure way without the new IP addressing structure.

Learn More:
Visit the link below to get benefit from our Lesson 8 which focuses on Routing and its types

Preparation of CCNA 100-101 Exam:
After getting all the technical knowledge about 100-101 exam, the candidate have to prepare for passing this exam. The practice tests are a best tool / way to prepare for the real 100-101 exam as it is a simulator of a real exam.