I was reading about NAT. It has 3 types.
- Static - one-to-one mapping between private and public addresses.
- Dynamic - one public address is selected from a pool of public addresses and mapped to one private address. This is also a one-to-one mapping.
- Overloading/PAT - in this case port numbers are going to play a role to map a set of private addresses to a public address or a much smaller set of public addresses.
In the first two case the NAT table is going to have IP address pairs, but in the last case the NAT table is going to have IP+port number pairs.
Also I read that when communicating different applications can be differentiated by port numbers.
My problem is: Lets consider a static NAT, where a local host is mapped to a global IP address. If this host runs multiple applications, and each application uses different port numbers in that case does the NAT table have port number mappings as well? In other words how requests from different applications from a particular host are handled/differentiated without port numbers in static NAT?