NAT (Network Address Translation) allows private IP addresses to be translated to public IP addresses to allow access to the internet. There are three types of NAT: static NAT maps a single private IP to a single public IP; dynamic NAT maps multiple private IPs to multiple public IPs; and PAT (Port Address Translation) maps multiple private IPs to a single public IP by multiplexing ports. The document provides configuration examples for static NAT, dynamic NAT, and PAT on Cisco routers to translate private to public IP addresses and allow internal hosts to access the internet.

1. Instructor & Todd Lammle Sybex CCNA 640-802 Chapter 11: Network Address Translation

5. Where NAT is typically configured

6. Basic NAT

10. Port Address Translation

11. PAT Here is a sample output of a PAT configuration: ip nat pool globalnet 170.168.2.1 170.168.2.1 netmask 255.255.255.0 ip nat inside source list 1 pool globalnet overload ! interface Ethernet0/0 ip address 10.1.1.10 255.255.255.0 ip nat inside ! interface Serial0/0 ip address 170.168.2.1 255.255.255.0 ip nat outside ! access-list 1 permit 10.1.1.0 0.0.0.255

12. What is your configuration?

13. NAT Lab example