Networking Fundementals Flashcards
What is a computer network?
▪ Complex systems that enable communication and data exchange
between multiple devices
What is a client?
- Devices that request and use resources provided by servers e.g. a computer
What is a server?
- Powerful computers that provide resources or services to
clients
What is a switch?
- They connect multiple devices on a Local Area Network (LAN), allowing them to communicate with each other
What is a router?
- Devices that connect multiple networks together and
direct data traffic between them
What is a modem?
- Devices that modulate and demodulate signals, enabling
communication over cable or telephone lines
What is a network interface card? (NIC)
- Hardware components that allow computers to connect to a network
What is an access point?
- Devices that create a Wireless Local Area Network (WLAN) or a wireless connection point for devices on an existing
wired network
What is a firewall?
- Security systems that monitor and control incoming and
outgoing network traffic based on predetermined security
rules
What are 3 different types of firewall and how do they work?
▪ Packet-Filtering Firewalls - check packets against a set of filters
▪ Stateful Inspection Firewalls - monitor active
connections
▪ Proxy Firewalls - mask the network’s internal IP addresses
What is a LAN?
▪ Local Area Networks (LAN)
● Network that connects devices in a relatively small area, such as a
home, office, or a group of buildings
What is a WAN?
▪ Wide Area Networks (WAN)
● Span a large geographical area, often connecting LANs that are
miles apart
What is a MAN?
▪ Metropolitan Area Networks (MAN)
● Larger than LANs but smaller than WANs, they typically cover a
city or a town
What is a CAN?
▪ Campus Area Networks (CAN)
● Networks that cover a specific geographic area like a university
campus or a military base
What is a PAN?
▪ Personal Area Networks (PAN)
● PANs can be wired, like a connection between a computer and a
printer, or wireless, like Bluetooth networks
What is an ISP?
o Internet Service Providers (ISPs) provide services that enable individuals and
organizations to access the internet
What are the benefits of wired networks and where may they be used?
▪ The physical connection of cables ensures a stable and consistent data
transfer rate, minimizing the risk of data loss or signal interference
▪ This reliability makes wired networks particularly suitable for
environments that require high data transfer rates and secure
connections
● Corporate Offices
● Data Centers
● Critical Infrastructure
What are the benefits of wireless networks and where may they be used?
▪ Wi-Fi is the most common example of a wireless network, allowing
devices to connect to the network within a certain range of the router
▪ This freedom of movement is particularly beneficial in environments
where mobility is essential
● Homes
● Coffee Shops
● Airports
What is the TCP/IP, also known as the Internet Protocol Suite?
o Transmission Control Protocol/Internet Protocol (TCP/IP)
▪ Conceptual framework that defines how data should be packaged,
addressed, transmitted, routed, and received on the internet
What are the 4 layers of the TCP/IP and what happens at each of the layers? Explain in terms of opening a web page
● Application Layer
Communicates directly with the software to create the data request e.g. user types web address into search bar, computer creates web page request
● Transport Layer
Creates a set of rules for the connection to ensure the data stays in the correct order, without duplication and error-free. E.g. source device handshakes with destination device, receives acknowledgment of data sent after internet layer
● Internet Layer
Uses IP to ensure the data goes to the right location and returns to the right location e.g source MAC address and destination IP is bundled with the data into a frame
● Network Interface Layer
Physically sends/recieves the frame over the network via the ethernet switch.
e.g. sends the frame to the ethernet switch which then sends the frame to the router, router then sends request to youtube
Process then happens in reverse.
Name the 2 main types of protocols in the transport layer?
▪ Transmission Control Protocol (TCP)
● Which provides reliable, connection
oriented communication
▪ User Datagram Protocol (UDP)
● Which provides connectionless, best-effort
communication
What is an IP address?
▪ Internet Protocol (IP) addresses
● Unique identifier assigned to each device connected to a network that uses the Internet Protocol for communication
What 2 parts does an IP address consist of?
● An IP address consists of two parts
Network ID - Identifies the specific network on which the device
is located
Host ID - Identifies the specific device on that network
Explain the two versions of IP address?
- IPv4 - Written as four sets of decimal integers separated by periods for example, 192.168.1.1
▪ Each set can range from 0 to 255
IPv6 - Written as eight groups of four hexadecimal digits, separated by colons, for example,
2001:0db8:85a3:0000:0000:8a2e:0370:7334
What is a MAC address?
● Unique identifier assigned to a NIC by its manufacturer
● MAC addresses consist of six groups of two hexadecimal digits,
separated by colons or hyphens, for example, 01:23:45:67:89:ab
What is Address Resolution Protocol used for?
● Used to map an IP address to a corresponding MAC address
What is switching used for?
● Network switches are devices that connect various devices on a LAN and use MAC addresses to direct data packets to their
intended destinations
What are WAN’s?
Wide Area Networks (WANs)
▪ Are integral to global communications, connecting Local Area Networks
(LANs) across cities, countries, or even continents
What is routing?
The process of selecting the most appropriate path for data packets to travel from a source device to a destination device across a network.
What is the routing process of sending data across different networks?
Examines the destination IP address
Routers then evaluate various factors
▪ Network Congestion
▪ Available Bandwidth
▪ Number of Hops (or the number of intermediate network devices the
packet needs to traverse)
Explain the domain name system (DNS)
o Domain Name System (DNS)
▪ A critical component of the Internet infrastructure, enabling the
translation of human-friendly domain names into IP addresses, and vice
versa
Explain DNS resolution in steps.
1) Device checks Local DNS Resolver Cache for a website’s IP address
2) If it does not have it it then asks the ISP
3) If the ISP doesn’t know it asks the Root DNS Server
4) The Root DNS Server directs the ISP to the correct domain name server as well as the authorising name server (e.g. .com)
6) The correct IP address is then sent back to the local DNS resolver
What is HTTP, and what port does it operate on?
HyperText Transfer Protocol (HTTP)
Port 80
How does HTTP work?
▪ HTTP protocol uses a client-server model, where the client sends
requests for resources and the server responds with the requested
content
What is HTTPS, and what port does it operate on?
HyperText Transfer Protocol Secure (HTTPS)
Port 443
How does HTTPS work and remain secure?
HTTPS employs encryption protocols, such as Secure Sockets Layer (SSL) or Transport Layer Security (TLS), to establish a secure connection between the client and the server
What is a SSL/TLS handshake?
When a client initiates an HTTPS connection with a server, a process called SSL/TLS handshake takes place. During this handshake, the client and server exchange public keys to establish a secure communication channel.
What is POP3 and what port does it operate on?
Post Office Protocol Version 3 (POP3)
● Operates on port 110 and is widely used for retrieving emails
from a mail server
● POP3 removes the email from the server once it has been
successfully downloaded
What is IMAP and what port does it operate on?
▪ Internet Message Access Protocol (IMAP)
● Operates on port 143 and allows multiple email clients to manage
the same mailbox while keeping the email stored on the server
● Actions performed on one device are synchronized across all
connected devices
What is SMTP and what port does it operate on?
▪ Simple Mail Transfer Protocol (SMTP)
● Operates on port 25 and serves as the standard protocol for
sending emails across the Internet
