1.4 Network Communication

Question 1

What is unicast communication?

Answer 1

Unicast is a one-to-one communication method where data is sent from one device directly to another and not shared with other devices on the network.

Transcript: “It is when one station sends information directly to another station… nothing within that conversation is ever sent to anyone else on the network.” (0:06–0:19)

Question 2

What are common use cases for unicast communication?

Answer 2

Unicast is typically used for web browsing, file transfers, and email communication—any scenario involving direct communication between two devices.

Transcript: “Any time you’re connecting to a website, you’re transferring files, or you’re checking your email…” (0:28–0:34)

Question 3

What is a major disadvantage of unicast when communicating with multiple recipients?

Answer 3

Each recipient must receive a separate stream, making unicast inefficient for sending the same data to multiple devices simultaneously.

Transcript: “You would have to build separate one-to-one communications… send separate data for each…” (0:48–0:57)

Question 4

What is multicast communication?

Answer 4

Multicast is a one-to-many-of-many communication model where data is sent once and received by multiple devices that are subscribed to a multicast group.

Transcript: “Multicast is a one-to-many-of-many communication… subscribed to your multicast feed.” (1:15–1:28)

Question 5

What are common use cases for multicast communication?

Answer 5

Multicast is used for streaming multimedia, distributing stock data, and sending routing updates to multiple devices simultaneously.

Transcript: “Trying to receive multimedia… receiving stock exchange information… routing updates…” (1:29–1:38)

Question 6

Why isn’t multicast used across the public internet?

Answer 6

Multicast requires network infrastructure that understands multicast traffic, making it impractical for use across large or public networks.

Transcript: “Requires that equipment understand and recognize how to deal with multicast… we don’t use multicast… across… the internet.” (1:41–1:54)

Question 7

What is anycast communication?

Answer 7

Anycast is a one-to-one-of-many communication method where data is sent to one of many devices with the same destination address, usually the nearest one.

Transcript: “One device needs to send to one of many devices… the closest is going to receive that traffic.” (2:12–2:46)

Question 8

What is a common application of anycast?

Answer 8

Anycast is commonly used in DNS, where a query is answered by the closest DNS server using the same IP address.

Transcript: “A good use case for anycast would be… anycast DNS… the closest data center will be able to respond…” (2:48–2:58)

Question 9

What is broadcast communication?

Answer 9

Broadcast is a one-to-all method where a single message is sent to all devices in the local broadcast domain.

• routing updates, ARP requests

Transcript: “Send a frame to everyone… one-to-all relationship… everyone on the network receives…” (3:01–3:15)

Question 10

Is broadcast supported in IPv6?

Answer 10

No. IPv6 removed broadcast entirely and replaced it with multicast communication.

“With IPv6… remove broadcast completely and go to a multicast form…” (3:35–3:42)