Switch and Router Technology-33-Static NAT

Network Address Translation NAT

1. Static transformation
2. Dynamic transformation
3. Port Multiplexing PAT
4. Port Mapping (Server Mapping)

NAT Basic Concepts

Because the network is divided into private network and public network in the ipv4 network environment, the address of the private network cannot be routed on the public network

Purpose:

Convert private network address to public network address

appears background

Due to the limited IP resources and the continuous increase of network devices, the IP address is not enough

Transformation:

Static and dynamic NAT are basically unnecessaryp>

Static translation IP address translation only 1 to 1

dynamic conversion only IP address conversion many-to-many

Case 1: There are more intranet addresses than extranet addresses, no way to go online at the same time

Case 2: The intranet address is less than the extranet address

Port multiplexing PAT multi-to-1 turn to carry the port to convert together 192.168.1.2:5252-à6423.54.99:6625

Distinguish which address is on the Internet according to the port

Port mapping (server mapping)

Publish an intranet server to the extranet so that hosts on the extranet can access the intranet server

192.168.1.1.:80----64.26.32.22:80

Destination address conversion

4 types of addresses in the conversion table

Internal local address: sender's intranet

External global address: sender's external network

External local address: the recipient's intranet

External global address: the recipient's external network

Static transition

Configure static NAT

Specify internal and external network interfaces

Router(config)#int g0/0

Router(config-if)#ip nat inside

Router(config)#int g0/1

Router(config-if)#ip nat outside

Configure on the router

Ip nat inside source static public network ip

View nat static conversion information