Understanding the internet Flashcards
What does IP stand for?
Internet Protocol
What is an IP address?
A label assigned to a device that is connected to the internet.
The label is a series of numbers.
What is IPv4 and IPv6?
IPv4 had about 4.3 billion addresses, but we have already way passed that, so IPv6 has like 3 gazillion addresses.
What is TCP?
Transmission Control Protocol.
It is a standardisation (protocol) for how computers can talk to each other.
What is UDP?
User Datagram Protocol
What is the difference between TCP and UDP?
TCP is lossless, it guarantees that if I send information it will be received. It has e.g. error correcting. UDP means you send information but you don’t know for sure it has been received.
TCP sends a SYM packet to ask ‘are you there?’ and then the client responds ‘yeah’ with an ACK, and then some more stuff and then the data gets sent.
Error correcting means that when a packet is sent to the server, the metadata can state e.g. that there are 50 packets coming in total, and then the server can wait and collect them, and then respond if it is missing any of the packets.
TCP negotiates the connection to the server every time a request is sent, but UDP leaves the connection open after the first connection.
What is DNS? How does it work?
Domain Name System.
An organisation called ICANN manages DNS. When you register a domain name, a small fee goes to them for this (like 60c).
It’s like an intelligent phone book, which looks up the IP address for the web address you typed in and then finds the closest server to you.
This ‘phonebook’ is kept on nameservers.
What is a GUI?
Graphical User Interface
What are the different parts of this web address: blog.jemyoung.com
.com - TLD - top-level domain
jemyoung. com - domain
blog. - subdomain
Why are subdomains useful rather than routes?
blog. jemyoung.com - this subdomain suggests that it’s like a whole different part of the site, that probably looks different to the rest as well
jemyoung. com/about - the about page is a part of the main site
What is a nameserver?
This is where the ‘phonebook’ of IP addresses is kept, so that you will be directed to the correct IP when you type in a web addresss.
What is ICMP?
Internet Control Message Protocol. Used by e.g. both ping and traceroute when checking if a server is there. You can program your server to not respond to ICMP, this is called black-holing, bc requests just never resolve.
What is a packet?
A little bit of information (like an envelope with information in it).
A base unit of information that all devices on the internet know how to communicate with.
A packet is mainly metadata.
How does the internet work?
The internet runs via TCP over IP, sending and receiving packets.
What is net neutrality?
Debate over whether internet providers should just be pipes transferring data, or whether they should prioritise traffic for profit.
