What Does PAT Mean in 200-301?
Full form: Port Address Translation
Also known as: Port Address Translation, NAT Overload, NAT overload
Quick Definition
A NAT variant that maps multiple private IP addresses to a single public IP using different port numbers.
Full Definition
PAT (also called NAT Overload) allows many devices to share a single public IP address by using unique source port numbers to distinguish each connection. When an internal host initiates a connection, PAT creates an entry in the translation table mapping the private IP:port to the public IP:unique-port. This is the most common form of NAT used in home routers and small businesses. PAT sessions are tracked in the NAT translation table.
CLI Command
ip nat inside source list 1 interface GigabitEthernet0/0 overload ! PAT using interface IP
Exam Trap — Don't Get Fooled
PAT uses the 'overload' keyword in the NAT configuration. Without 'overload', you get dynamic NAT (one public IP per private IP from a pool), not PAT.
Related 200-301 Terms
Frequently Asked Questions
What does PAT mean on the 200-301 exam?
PAT (also called NAT Overload) allows many devices to share a single public IP address by using unique source port numbers to distinguish each connection. When an internal host initiates a connection, PAT creates an entry in the translation table mapping the private IP:port to the public IP:unique-port. This is the most common form of NAT used in home routers and small businesses. PAT sessions are tracked in the NAT translation table.
How does PAT appear as a trap on the 200-301?
PAT uses the 'overload' keyword in the NAT configuration. Without 'overload', you get dynamic NAT (one public IP per private IP from a pool), not PAT.
How important is PAT on the 200-301 exam?
PAT falls under the IP Services domain of the 200-301 exam. Understanding it in context with related terms like nat and acl is essential for answering scenario-based questions correctly.