The Internet Flashcards
(49 cards)
How do we define the internet?
A network which connects other LANS together
What is the intranet?
It is a private network accessible only to employees within an organisation, used for internal communication and collaboration.
What is the extranet?
Private network that allows controlled access to external parties like customers or partners and suppliers allowing them to share specific information with the company while maintaining security
What information does a URL contain?
-The protocol used to access resource
-The location of the server
-The port number on the server(optional)
-The location of the resource in the directory structure of the server
What does each part of the domain name tell us?
http://www.davescomputertips.com/Newsletters/20070915.php
http-protocol
www-world wide web(network)
Davescomputertips-domain name
.com-top level domain
Newsletters-hostname folder
20070915-file name
php-file extension
What is a URL?
The address of a resource on the internet
What is a Domain Name?
The recognisable name of a domain on the inter dot which maps to an IP address.
What is an IP address?
A numerical representation of a domain name e.g 234.15.215.123
What is an IP address made of?
4 bytes-32 bits using IPv4
What are different parts of the IP address for?
The first part is network identifier and second part is host identifier
What is the purpose of the DNS?
A database of FQDNS and corresponding IP addresses which finds IP address mapped to a domain name to locate URLS which load internet pages
If the domain name can’t be translated to an IP address on one server what happens?
It will forward to other DNS servers to find the address
Why may a DNS not always be required
You can access websites by directly typing in IP address and sometimes it is stored locally if website regularly visited
What is a FQDN?
A fully qualified domain name is the complete domain name for a specific computer. This consists of two parts: the hostname and domain name
What is a port?
Doors or channels on a computer or device that help it send or receive data, and used to identify a particular process or application on a network
What is a common port for websites?
Port 80
What is SSH?
Secure shell protocol is for remote access to computers with extra security.
What is port scanning?
A technique used to identify open ports on a computer or network device and helps determine which ports are active and what services are running on these ports
What does a port scanner send requests to ports to check?
If port is open-the device responds indicating it’s in use
If port is closed-device doesn’t respond or send rejection message
If port is filtered-a firewall or security measure blocks request
How can port scanning be used maliciously?
To search for vulnerable servers and discover organisations security levels
What does a private or non routable IP address mean?
An IP address that consists of reserved numbers used to communicate with each other within a private network and can’t be directly accessed or routed by internet.
What is NAT?
A networking process that allows multiple devices on a private network to share a single IP address to access the internet
What are two advantages of using NAT?
-A unique address is not used for every device
-Security-as private IP address are not broadcast over internet
What is Port forwarding?
The technique used to transmit data from a private network to public network where router will forward data to original request by device in private network using devices specified port
