Introduction to Routing and Switching Week 1 - Part 2 Models, Addressing, Wireshark

What is a network?

A telecommunications system that connects computers to allow communication and data exchange.

What is network topology?

The way in which network components are arranged or interrelated.

What is a protocol?

A set of rules for communication between devices (data format, addressing, routing, error detection, acknowledgements).

What is a standard?

A defined format or rule set for technologies.

What is a de facto standard?

An industry-accepted standard.

What is a de jure standard?

A formally approved standard by official organizations.

What does ISO stand for?

International Organization for Standardization.

What does IEEE stand for?

Institute of Electrical and Electronics Engineers.

What does IETF stand for?

Internet Engineering Task Force.

What is the OSI model?

A conceptual framework used to understand and organize networking functions into layers.

What is the TCP/IP model?

A reference model based on a real protocol suite used on the internet.

Who developed the OSI model?

ISO.

Who developed TCP/IP?

The Department of Defense (DARPA).

How many layers are in the OSI model?

7.

What does the Application layer do?

Provides user interface and network services.

What does the Presentation layer do?

Handles data translation, encoding, and compression.

What does the Session layer do?

Manages sessions (start, maintain, end communication).

What does the Transport layer do?

Provides end-to-end communication, reliability, segmentation, and retransmission.

What does the Network layer do?

Handles logical addressing, routing, and forwarding.

What does the Data Link layer do?

Handles physical addressing, error detection, and media access.

What does the Physical layer do?

Handles signaling, cabling, and hardware.

What is a Protocol Data Unit (PDU)?

The unit of data at each OSI layer.

Name Application layer protocols.

HTTP, FTP, SMTP, DNS.

Name Transport layer protocols.

TCP and UDP.

Name Network layer protocols.

IP, ICMP, RIP.

What is a MAC address?

A unique 48-bit physical address assigned to a network interface.

How is a MAC address written?

As 12 hexadecimal digits (e.g., 6C:F0:49:68:95:68).

What is an OUI?

The first 24 bits of a MAC address identifying the vendor.

What is the second half of a MAC address?

A unique serial number assigned by the vendor.

What is a broadcast MAC address?

FF:FF:FF:FF:FF:FF (sent to all devices on a LAN).

What is a multicast MAC address?

An address used to send to a group of devices.

What is a unicast MAC address?

An address used for one-to-one communication.

What is an IPv4 address?

A 32-bit logical address used to identify devices on a network.

What are the two parts of an IP address?

Network portion and host portion.

What does a subnet mask do?

Identifies which part of the IP address is network vs host.

How many bits are in an IPv4 address?

32 bits.

How many possible IPv4 addresses exist?

About 4.3 billion.

What is dotted decimal notation?

IP format using four decimal numbers separated by dots.

What is a Class A default mask?

255.0.0.0 (/8).

What is a Class B default mask?

255.255.0.0 (/16).

What is a Class C default mask?

255.255.255.0 (/24).

What is an IP broadcast address?

255.255.255.255 (sent to all devices on a network).

Are IP broadcasts routable?

No.

What is an IP multicast address?

An address used to send data to a group of hosts.

What is a unicast IP address?

Used for one-to-one communication.

What is the loopback address?

127.0.0.1 (tests the local device).

What is a network address?

An address where the host portion is all zeros.

What is APIPA?

Automatic Private IP Address assigned when DHCP fails.

What is encapsulation?

The process of adding headers as data moves down OSI layers.

What is de-encapsulation?

Removing headers as data moves up OSI layers.

What is Wireshark?

A network protocol analyzer used to capture and inspect traffic.

What is another name for Wireshark?

Packet sniffer.

What can Wireshark do?

Capture, analyze, and display network traffic in real time.