Network Address Translation (NAT)

Understand Network Address Translation (NAT), including how to configure NAT on a router and its importance in network management.

Network Address Translation (NAT)  

Understanding NAT  

NAT translates private IP addresses to a public IP address for accessing the internet. This allows multiple devices on a local network to share a single public IP address.

Types of NAT  

• Static NAT: One-to-one mapping between local and global addresses.
• Dynamic NAT: Many-to-many mapping between local and global addresses.
• PAT (Port Address Translation): Many-to-one mapping using ports.

Configuring NAT  

Configuring Static NAT  

Static NAT is used for one-to-one mapping between a local IP address and a public IP address.

# Example: Configuring Static NAT
ip nat inside source static 192.168.1.10 203.0.113.10
interface GigabitEthernet0/0
 ip nat inside
interface GigabitEthernet0/1
 ip nat outside

Configuring PAT  

PAT allows multiple devices on a local network to share a single public IP address by using different port numbers.

# Example: Configuring PAT
ip nat inside source list 1 interface GigabitEthernet0/1 overload
access-list 1 permit 192.168.1.0 0.0.0.255
interface GigabitEthernet0/0
 ip nat inside
interface GigabitEthernet0/1
 ip nat outside