Which statement correctly describes PAT's behavior?

Which statement correctly describes PAT's behavior?

• A. A dedicated public IP per private IP
• B. PAT uses a single public IP address to translate many private IP addresses
• C. PAT translates private IPs to a public IP for each session
• D. PAT is unrelated to NAT

Answer: (B)

PAT is a form of NAT that overloads a single public IP to support many private addresses. It works by mapping each internal connection to a unique port on that public IP. When internal hosts access the Internet, the router rewrites the source IP to the public IP and assigns a unique source port; a translation table keeps track so the return traffic can be delivered to the correct internal host. This lets many devices share one public IP, which is why the statement is correct. The idea of one public IP per private IP would be static NAT, not PAT. The notion of a public IP being used for each session is misleading because PAT reuses the same public IP for multiple sessions, distinguished by ports. And PAT is a type of NAT, not something unrelated to NAT.

PAT is a form of NAT that overloads a single public IP to support many private addresses. It works by mapping each internal connection to a unique port on that public IP. When internal hosts access the Internet, the router rewrites the source IP to the public IP and assigns a unique source port; a translation table keeps track so the return traffic can be delivered to the correct internal host. This lets many devices share one public IP, which is why the statement is correct. The idea of one public IP per private IP would be static NAT, not PAT. The notion of a public IP being used for each session is misleading because PAT reuses the same public IP for multiple sessions, distinguished by ports. And PAT is a type of NAT, not something unrelated to NAT.