Networking: Chapter 3 (IP Addresses and the Domain Name Service) Flashcards
What is an IP address?
They are used to address and route packets across networks
How are IP addresses constructed?
They are split into 4 x 8 bit numbers, which are called octets
What numbers are reserved for special purposes?
0, 127 and 255
How many possible IP addresses can there be?
2^32
What is a Class A IP address? Who would a Class A IP address be given to?
- When only the first octet is assigned a number initially, and the other three octets can be assigned by the owner
- A multinational corporation such as Apple or IBM
What is a Class B IP address? Who would a Class B IP address be given to?
- When the first and second octet are assigned with a number initially, and the other two octets can be assigned by thee owner.
- A large organisation such as a university or major hospital
What is a Class C IP address? Who would a Class C IP address be given to?
- When the first, second and third octets are assigned a number initially, and the other octet can be assigned by the owner.
- A small company with few employees.
What is Static IP addressing?
This is when every machine on a network has a fixed address
What is Dynamic IP addressing?
This is when an IP address is allocated to a machine on a network from a pool of addresses
Why are Domain Names used?
To translate user friendly domain names into IP addresses so a computer can understand them
How does the Domain Name Server use a web address to access a website? (3)
- The DNS looks up a URL in its database
- The DNS translates the URL into an IP address
- The DNS returns the IP address to the user’s machine
What are the ranges of the first octets for Class A, B and C IP addresses?
- Class A = 1-126
- Class B = 128-191
- Class C = 192-223
