TCP/IP Architecture

Function

100

What is the function of the Application Layer?

Connects users and apps (services)

200

What is the function of the Transport Layer?

Connects processes from one host to another host (reliability)

300

What is the function of the Network Layer?

Connects networks; routes traffic across Internet

400

What is the function of the Data Link Layer?

Connects hosts on the same local area network

500

What is the function of the Physical Layer?

Connects two devices

Protocols

100

What are some of the primary protocols at the Application Layer along with their common associated ports?

HTTP (80)

HTTPS (443)

SSH (22)

DNS (53)

DHCP (67/68)

200

What are the two main protocols at the Transport Layer?

Transmission Control Protocol (TCP), User Datagram Protocol (UDP)

300

What are the two main protocols at the Network Layer?

Internet Protocol (IP), Internet Control Messaging Protocl (ICMP)

400

What are some protocols at the Data Link Layer?

Ethernet (IEEE 802.3), WiFi (IEEE 802.11), LTE/5G

500

How is information represented at the Physical Layer?

Voltages, RF Signals

Data Units

100

What is the data unit for the Application Layer?

Data or Messages

200

What are the data units at the Transport Layer?

Segments (for TCP), Datagrams (for UDP)

300

What is the data unit at the Network Layer?

Packets

400

What is the data unit at the Data Link Layer?

Frames

500

What is the data unit at the Physical Layer?

Bits or Bytes

Addressing

100

What is used for addressing at the Application Layer?

Trick question! The Application Layer doesn't do any addressing.

200

What is used for addressing at the Transport Layer?

Port Number

300

What is used for addressing at the Network Layer?

IPv4 or IPv6

400

What is used for addressing at the Data Link Layer?

Media Access Control (MAC) Address

500

What is used for addressing at the Physical Layer?

Trick question!  The Physical Layer does not do any addressing.

Hardware or Commands

100

What is a command you can use at the Application Layer for querying the Domain Name System to obtain domain name or IP address mapping?

nslookup

200

What is a command you can use at the Transport Layer for network statistics?

netstat

300

What is the primary piece of hardware that operates at the Network Layer

Router

400

What is the primary piece of hardware that operates at the Data Link Layer?

Switch

500

What is the primary piece of hardware that operates at the Physical Layer?

Hub