Network Flashcards
Computer Network Definition
A group of computers that use the same set of communication protocol to share resources over digital connections
Intranet Definition
Definition: A private network within organisations that usually excludes outsider excess
Virtual Private Network (VPN) Definition
Encrypted connection over the internet from a device to a network
Internet Definition
worldwide network of networks that uses the Internet Protocol (IP) suite
World Wide Web (WWW) Definition
a network of public web pages available on the internet
LAN vs WAN?
LAN is a computer network that connects computers over a small geographical area, while WAN covers a large geographical area
TCP/IP Model?
(Hint: Recall NITA)
Application, Transport, Internet, Network Access Layer
Internet Protocol address (IP address)
a numerical label assigned to each device connected to a computer network that uses the Internet Protocol for communication
Types of IP address?
IPv4 and IPv6
What is the IPv4 exhaustion problem? What are the solutions?
the depletion of the pool of unallocated IPv4 addresses due to the dramatic growth of the internet
solution: deployment of IPv6
Uniform Resource Locator (URL) Definition
a reference to a web resource that specifies its location on a computer network
Domain Name System (DNS) Definition
a hierarchical and decentrailised database that converts URLs to their associated IP addresses
What is the DNS query process?
- Client opens the web browser and types in the uniform resource locator (URL) in the address bar
- URL request is sent to the recursive server and checks if the domain name is found in its local cache. If it does, continue to step 7. Otherwise, continue to step 3
- Recursive server sends the request to the DNS root name server to obtain information on the top-level domain (TLD)
- Recursive server sends the request again to the TLD name server to obtain information on the second-level domain (SLD)
- Recursive server sends the request again to an authoritative name server to obtain information on the domain and its associated IP address
- Authoritative name server sends the IP address back to the recursive server
- Recursive server sends the IP address back to client through the web browser. Recursive server also caches the IP address for the domain
- Once IP address is received it will build a connection with the web server that matches the IP address
- Once connection is establishes, web browser will send a HTTP request to the web server
- Web server sends a HTTP response to the web browser. Web browser displays the information is has obtained.
Communication Protocol Definition
A set of rules that define the format, order of information exchange, and the actions taken after the information is transmitted over the network
Protocol Standards Purpose?
To prevent manufacturers from creating their own protocol, and discouraging users from using equipment from other manufacturers
Transmission Control Protocol (TCP) vs User Datagram Protocol (UDP)
TCP is a connection oriented protocol that requires a connection to be established before transmitting segments
UDP is a connectionless protocol that transmits datagrams continuously and disregards any issues on the receiving end
What is the TCP 3-way handshake?
Client sends a request to the server for a connection to be establishes, server sends a response back to acknowledge the client and client sends a response back to acknowledge the server
What are the methods of data exchange in a computer network?
Circuit Switching and Pack Switching
Circuit Switching Definition
Process where two network nodes establish a dedicated communications channel through the network before the nodes may communicate
Packet Switching Definition
Process where messages are broken down into small blocks called packets or datagrams, which are routed individually through the network to the same destination
Client-Server Architecture Definition
Tasks are partitioned between providers of service and service requesters
Peer-to-Peer Network Definition
Tasks are partitioned between peers, who are equally privileged participants in the application
Client-Server Architecture BENEFITS
- Easy to manage as all files are stored in the same place. This allows for easy and efficient back-up and recovery
- Easily scaled up and upgraded as only servers have to be changed
- Secure as rules can be defined at the time of setting up the network
- Accessible, where servers can be accessed remotely from various platforms of the network
Client-Server Architecture CONSTRAINTS
- Expensive to install and manage
- Prone to congestion, when too many requests from the clients are sent
- Less reliable as the failure of the server results in the client being dysfunctional
