<<
There are four types of NAT:
1. Static NAT. Static NAT is the simplest to set up. Each host on the internal network is permanently mapped to a legal address on the external network. This type of NAT is used in many internal firewall planning scenarios.
2. Pooled NAT (also known as Dynamic NAT). In dynamic NAT, the post-NAT address is not fixed; it is dynamically assigned from an IP address pool.
3. Overloading NAT (also known as PAT). PAT is the NAT application most people are familiar with. In dynamic translation, each legal IP address can only be used once in the translation table. When internal network hosts require increased external access, the IP addresses in the legal address list quickly run out. This is where upper-layer protocol identifiers, such as TCP/UDP port numbers in the transport layer, can be used to assist in building NAT translation entries.
4. Overlapping NAT. This occurs when the addresses used on the internal network overlap with those on the external network. In this case, the overlapping IP addresses need to be translated. This type of translation is generally applied when the private network addresses on both ends of the translation are identical.
Today, using an enterprise network project as an example, the author guides you into the world of enterprise network management. In this project, there’s a networking term that most readers are familiar with——NAT (Network Address Translation). So, what exactly is the role of NAT, and what functions can it achieve in enterprise-level applications?
