Computing - Structure of the Internet
What is the largest network in the world called?
The Internet.
What is the World Wide Web?
The collection of resources that can be accessed via the Internet.
What is main part of the Internet called?
The backbone.
What is the backbone?
The set of connections that connect large networks at various points on the globe.
If the backbone is at the bottom of the hierarchy of the Internet, what is next?
Regional networks.
Who controls regional networks?
ISPs
What goes on top of regional networks in the hierarchy of the Internet?
Home networks.
What protocol is used to uniquely identify devices on a network?
The Internet Protocol
What does an IPv4 address consist of?
$4$ octet values.
What is an octet?
Numerical values described by $8$ bits.
In an IPv4 address, how many bits are used for each component?
$8$ bits.
How many unique addresses do IPv4 provide?
$3.4$ billion.
What is the purpose of a URL?
To specify how and where you can access a resource across a network.
What are the two components of a URL?
- The protocol
- The domain name
What does URL stand for?
Uniform Resource Locator
What is the purpose of DNS?
To convert domain names to their IP addresses.
What is missing?
root
What is missing?
Generic TLDs
What is missing?
Country TLDs
What is missing?
2LDs
What is missing?
3LDs
Who controls which domain names are allocated to which IP addresses?
Internet Registries
What do internet registries work together to maintain?
A database of domain names and their corresponding addresses.
If a client has no cached record of an IP address for “www.google.co.uk”, what will it do?
Sends a query for that domaint to a DNS server.
If a DNS server knows about a certain domain name, what two things can it respond with?
- An error saying it’s not found
- The IP address
If a DNS server doesn’t know about a certain domain name, what does it response with?
A referal to a lower-level DNS server.
2021-02-11
In “https://www.google.co.uk/search”, what is “www.google.co.uk” called?
The fully-qualified domain name.