CompTIA Network+ (N10-009)Networking ConceptsMedium
A company's edge router translates a single internal server's private IP address to one specific public IP address at all times so external clients can consistently reach it. Which technique is being used?
- ADynamic NAT
- BPort Address Translation (PAT)
- CStatic NAT
- DAnycast routing
Show answer & explanationAnswer & explanation
Correct answer: C. Static NAT
Static NAT creates a fixed, one-to-one mapping between a single private IP address and a single public IP address, ensuring the mapping never changes, which is ideal for servers that must be consistently reachable from the internet.
Why the other options are wrong
- A. Dynamic NAT assigns public addresses from a pool on a first-come basis, not a fixed mapping.
- B. PAT maps many private IPs to one public IP using different port numbers, not a one-to-one mapping.
- D. Anycast assigns the same IP to multiple geographically distributed servers, unrelated to NAT.
Static NAT
Static NAT is a fixed one-to-one translation between a single private IP address and a single public IP address.
- Mapping never changes
- Commonly used for servers needing consistent external reachability
- Different from PAT, which multiplexes many hosts on one public IP using ports
Memory trick: Static NAT is a 'one-to-one marriage' of IP addresses that never divorces.