This document discusses Network Address Translation (NAT) and how it allows private IP networks to connect to the Internet. It covers the problems of IP address exhaustion and depletion of IPv4 addresses. NAT enables private networks using unregistered IP addresses to connect to the public network by translating private IP addresses to public IP addresses. The document defines key NAT terms and describes how NAT is implemented on a router with inside and outside interfaces to translate packet headers. It also covers the types and advantages of NAT, including connecting multiple computers to the Internet using a single public IP address, as well as some disadvantages like added delay.

1. NETWORK ADDRESS
TRANSLATION
LETS SEE HOW OUR ADDRESSES ARE TRANSLATED

2. TODAY’S AGENDA
• The Problem:- IP Address Exhaustion.
• The core solution.
• NAT: What it does ?
• How it works ?
• Part of implementation.
• Terminologies
• Types of NAT.
• Simulation
• Advantages and Disadvantages

3. IP ADDRESS EXHAUSTION
• Depletion of the pool of unallocated IPV4 address.
• 4.2 billion addresses for 7 billion people on planet.
How to deal with it ?

4. THE INTACT SOLUTIONS
• Private network.
• Virtual hosting.
• Sub-netting.
• Network Address Translation.
• IPv6

5. N.A.T
• Address translational protocol
• Enables private IP networks that use
unregistered IP addresses to connect to the
Internet

6. PRIVATE AND PUBLIC IP
ADDRESSES
CLASS PRIVATE ADDRESS PUBLIC ADDRESS
CLASS A 10.0.0.0-
10.255.255.255
1.0.0.0-
9.255.255.255
11.0.0.0-
126.255.255.255
CLASS B 172.16.0.0-
172.31.255.255
128.0.0.0-
172.15.255.255
172.32.0.0-
191.255.255.255
CLASS C 192.168.0.0-
192.168.255.255
192.0.0.0-
192.167.255.255
192.169.0.0-
223.255.255.255

7. HOW NAT WORKS ?
• NAT allows a single device, such as a router, to
act as an agent between the Internet or (public
network) and a private network.
• Which means:
• Only a single unique IP address is required to
represent an entire group of computers to anything
outside their network

10. PART OF IMPLEMENTATION
• Configured on Router.
• Need of two interfaces of routers, Outside/Inside
• Set of command instructions.
• a set of rules for translating the IP addresses in the
packet headers.

11. PRACTICAL LIFE
IMPLEMENTATION
• Enabling private IP addresses to communicate
over Internet.
• Merging two Networks, Using same IP
addresses.
• To connect multiple computers with internet
through the Single Public IP address.

12. TERMINOLOGIES
TERM DESCRIPTIO
N
Inside Local IP
Address
Before translation
source IP address
located inside the
network.
Inside Global IP
Address
After translation
IP address located
outside the local
network.
Outside Global IP
Address
Before translation
destination IP address
located outside the

13. TYPES OF N.A.T
• Static NAT
• We manually map each inside local IP address with
inside global IP address.
• Since it uses one to one mapping we need exactly same
number of IP address on both sides.
• Dynamic NAT
• We create a pool of inside global IP addresses.
• Let the NAT device to map inside local IP address with
the available outside global IP address from the pool
automatically.

14. ADVANTAGES OF N.A.T
• NAT solves IP overlapping issue.
• NAT hides internal IP structure from external
world.
• NAT allows us to connect with any network
without changing IP address.
• NAT allows us to connect multiple computers
with internet through the single the public IP
address

15. DISADVANTAGES OF N.A.T
• NAT adds additional delay in network.
• Several applications are not compatible with
NAT.
• End to end IP traceability will not work with
NAT.
• NAT hides actual end device.

16. SIMULATION

17. THANK YOU