NAT

-NAT is the process of mapping one IP to another IP
-NAT is used to save public IP
-It provides security by hiding the internal IP

Types of NAT

-Static NAT (one to one)

• One private IP is mapped to one public IP
• Generally used for hosting public servers

-Dynamic NAT (many to many)

• Many private IPs are mapped to many public IPs
• Can only be configured for outbound trafiic

-PAT (many to one)

• Many private IPs are mapped to one public IP
• All users can access internet at the same time
• Can only be configured for outbound traffic

-Practically what we do is dynamic source or destination NAT which depends on the purpose
-In case of accessing a public hosted web server, we are using a dynamic destination NAT rule, where all the requests coming to the public IP of that web server will be mapped to a internal private IP
-A group of internal users accessing internet can be done using a dynamic source NAT rule, where all the internal requests are mapped to a external public IP