How does NAT allow a home with 50 devices to share a single Public IP address?
- A It dynamically assigns a unique, globally reachable public IP address to every individual physical device whenever it first attempts to join the local subnet.
- B It utilizes a high-level IPv6 tunneling protocol to encapsulate standard 32-bit packets within a larger, more modern 128-bit routing architecture.
- C It rewrites the source IP and Port of outgoing packets to match the router's public identity, maintaining an internal translation table to route returning replies.
- D It acts as a primary network-level firewall that automatically blocks all incoming data packets from reaching any device with a non-standard internal identifier.
IPv4 only allows for roughly 4 billion addresses, which is not enough for every gadget on earth. NAT (Network Address Translation) allows an entire home or office to share just one public IP. The router acts as a 'concierge': when your laptop sends a packet, the router swaps your private IP (e.g., `192.168.1.5:443`) with its own public IP and a unique port. It records this swap in a table. When the response comes back, the router looks at the port, finds your laptop in its table, and forwards the data. While this saves addresses, it makes peer-to-peer connections (like gaming or VoIP) difficult because external devices cannot easily 'initiate' a connection with a device hidden behind NAT.
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