The Bits and Bytes of Computer Networking 6 Flashcards
What is a registrar?
An organisation responsible for assigning individual domain names.
What are hosts files? Why do modern computers still have one?
The original way IP addresses were mapped to domain names. A hosts file is a list of IP addresses followed by the corresponding domain name.
For the loopback address.
What is a loopback address, and give the IPv4 and IPv6 loopback addresses.
An address that always points to itself - traffic never leaves the node.
IPv4 = 127.0.0.0/8 IPv6 = ::1
What is a malicious way to use hosts files?
As they are consulted before a DNS resolution occurs, you can trick a computer think that a certain domain name points to a certain IP address, and redirect users’ traffic.
What is the cloud?
A global network of remote servers that operates as a single ecosystem.
What is hardware virtualization?
A core concept of cloud computing, the creation of a virtual machine that acts like a real computer with an operating system.
What is a hypervisor?
Software that creates and runs virtual machines (VMs). A hypervisor allows one host computer to support multiple guest VMs by virtually sharing its resources, such as memory and processing.
What are hosts and guests in cloud computing and how does the hypervisor interact with them?
A hypervisor allows one host computer to support multiple guest VMs by virtually sharing its resources, such as memory and processing.
What is a public cloud, and how can it be useful?
A large cluster of machines run by another company. You can pay to have the company host your DNS servers, databases etc, instead of buying your own. (is cheaper and less risk of losing data)
What is a private cloud?
Used by a single corporation, many smaller servers operate on one physical server.
What is a hybrid cloud?
When companies have some, usually sensitive, data on private clouds, but entrust their less sensitive servers to a public cloud.
What do the following stand for? Describe the meaning of the terms, including an example of each.
1 XaaS
2 IaaS
3 PaaS
4 SaaS
1 X as a Service = various executions of cloud computing.
2 Infrastructure as a Service = Instead of building your own networks, servers etc, pay someone to provide them as a service.
3 Platform as a Service = An execution engine is provided for whatever software someone wants to run, eg a web developer building an app needs an environment for it to run in.
4 Software as a Service = Licensing software to others, while keeping it centrally hosted and managed. eg gmail for business - trusting google to handle your email service.
How many bits are in an IPv6 address, and how are they represented?
128 bits - 8 groups of 4 hex numbers.
What are 2 ways to shorten an IPv6 address?
1 Remove leading 0s from a group.
2 Any consecutive groups of only 0s can be represented by a double colon (only once per address)
What is a link local address?
An IP address that is valid only for communications within the network segment.
