CCNA in Hindi - Network Addess Translation

NAT stands for Network address translation and the name specifies that it translates one address into another.

NAT can be used in various scenarios, some most common usage are;

1. Translating an IPv4 Private Address to IPv4 Public Address

2. Translating an IPv4 address into IPv6 Address

3. Translating an IPv4 Address into another IPv4 address, if the addresses ovelap


NAT can be configured on a variety of device including, Windows/Linux Server, Firewalls and Routers.

Following videos explain in detail various NAT flavours and their configuration on Cisco Routers;


CCNA in HINDI - Network Address Translation Part 1-6

CCNA in HINDI - Network Address Translation Part 2-6

CCNA in HINDI - Network Address Translation Part 3-6

CCNA in HINDI - Network Address Translation Part 4-6

CCNA in HINDI - Network Address Translation Part 5-6

CCNA in HINDI - Network Address Translation Part 6-6

CCNA in Hindi - IP Access Control Lists

What does a router do? It receives traffic on one interface, checks its routing table for the destination network in the packet, and if a route exists, forwards the packet through the outgoing interface present in the route.

A router drops a packet, only if it doesn't find a route for the destination in it's routing table. What if we want the router to drop some packets for us? We can do so by specifying criteria to select packets to drop, by using Access Control Lists or ACL. To filter IP traffic we use IP ACL.

An ACL is a list of rules defined by the administrator that specifies what kind of traffic is permitted through the router. The criteria to select packets can be based on Source and/or Destination IP address, protocol and source and/or destination port nos.


Following six part video series explains various kinds of IP ACLs and their configuration on CISCO routers;


CCNA Hindi - IP Access Control List Part 1

CCNA Hindi - IP Access Control List Part 2

IP Access Control List Part 3

CCNA Hindi - IP Access Control List Part 4

CCNA Hindi - IP Access Control List Part 5

CCNA Hindi - IP Access Control List Part 6