Network Services

NAT and PAT Fundamentals

Learn how NAT and PAT translate addresses and transport identifiers, how return traffic finds the correct private session, and where related features fit.

Intermediate12 min read
Network Services lessonNetworkingPractice

UNTIMED COACHING

Practice before the pressure

Use feedback to correct the model, not merely memorize an option position.

GUIDED PRACTICE

Practice the lesson questions

Answer normal lesson questions without a timer. Every answer includes an explanation, and incorrect answers can be tried again before continuing.

CONCEPT MODELS

See the lesson as a system

Use these visual guides to connect the key ideas before answering the questions.

PAT session translation pathPAT pairs address and transport information across a boundary.
PAT session translation pathA flow from internal client through translation device to external service and back.
Internal clientStarts an internal conversation
PAT bindingPairs addresses with ports
Translation deviceChanges packet representations
External serviceReceives translated traffic
Identifiers distinguish sessionsA shared outside address can represent separate conversations through transport identifiers.
Identifiers distinguish sessionsTwo internal clients connect through one outside address using different translated ports.
Client AUses one private tuple
Client BUses another private tuple
Shared addressRepresents outside traffic
Port mapping ADistinguishes one session