In the five-tuple description, which elements are included?

In the five-tuple description, which elements are included?

• A. The five-tuple includes source IP, destination IP, source port, destination port, and IP protocol number
• B. It includes user account names
• C. It includes only IP addresses
• D. It includes device hardware IDs

Answer: (A)

A five-field set identifies a specific network connection by combining who is talking, where they’re talking to, and how the conversation is carried. The fields are the source IP address, the destination IP address, the source port, the destination port, and the IP protocol number. The IP protocol number tells the stack which upper-layer protocol is in use (for example, TCP or UDP), so this, with the two addresses and two ports, uniquely identifies a particular flow. The other options don’t fit because user account names, hardware IDs, or focusing only on IP addresses aren’t part of this transport-layer connection identifier.

A five-field set identifies a specific network connection by combining who is talking, where they’re talking to, and how the conversation is carried. The fields are the source IP address, the destination IP address, the source port, the destination port, and the IP protocol number. The IP protocol number tells the stack which upper-layer protocol is in use (for example, TCP or UDP), so this, with the two addresses and two ports, uniquely identifies a particular flow. The other options don’t fit because user account names, hardware IDs, or focusing only on IP addresses aren’t part of this transport-layer connection identifier.