ITPEC FE Morning April 2022 Question 30
ITPEC FE Morning April 2022 — Question 30 of 80
NAPT (IP Masquerade) — allows multiple devices to share a single global IP address.
Device A is a router with one global IP on its WAN interface. Multiple PCs behind it use private IPs.
NAPT (Network Address Port Translation) translates each PC's private_IP:port → global_IP:unique_port, enabling all PCs to access the Internet through one public address.
Why not others:
- (a) DHCP — automatically assigns IP addresses to devices, does not translate addresses
- (c) Packet filtering — firewall function that filters traffic by rules, unrelated to address sharing
- (d) PPPoE — authentication protocol for establishing ISP connections (common in FTTH/DSL), not address translation
Key rule: When the question says "sharing a single global IP among multiple devices" → the answer is NAPT (or PAT/IP masquerade).
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