5. What is an IP addressWhat is an IP address
A way to identify machines on a network
A unique identifier
6. IP usageIP usage
Used to connect to another computer
Allows transfers of files and e-mail
7. IP structureIP structure
IP addresses consist of four sections
Each section is 8 bits long
Each section can range from 0 to 255
Written, for example, 128.35.0.72
8. IP structureIP structure
These four sections represent the machine
itself and the network it is on
The network portion is assigned.
The host section is determined by the
network administrator
9. IP structureIP structure
5 Classes of IP address A B C D and E
Class A reserved for governments
Class B reserved for medium companies
Class C reserved for small companies
If you want to connect to another computer, transfer files to or from another computer, or send an e-mail message, you first need to know where the other computer is - you need the computer's "address." An IP (Internet Protocol) address is an identifier for a particular machine on a particular network; it is part of a scheme to identify computers on the Internet. IP addresses are also referred to as IP numbers and Internet addresses
An IP address consists of four sections separated by dots.
Commonly written in decimal Each section contains a number ranging from 0 to 255. Example = 128.35.0.72
These four sections represent both the machine itself, or host, and the network that the host is on. The network portion of the IP address is allocated under authority of the Internet Assigned Numbers Authority (IANA). American Registry of Internetwork Numbers (ARIN) Network administrators then assign the host portion of the IP address to the machines on the networks that they operate
Which sections of the IP address represent the network and which sections represent the machine will depend on what "class" of IP address is assigned to a network.
There are 5 classes of IP addresses: Class A, Class B, Class C, Class D, and Class E.
Class A - supports 16 million hosts on each of 127 networks
Class B - supports 65,000 hosts on each of 16,000 networks
Class C - supports 254 hosts on each of 2 million networks
Classes correspond either to the size of the network (the number of hosts that the network can support) or are reserved for specific purposes, such as multicasting and experimentation.
The diagram shows Class A, Class B and Class C IP addresses. The blue numbers represent the network and the red numbers represent hosts on the network. As has been mentioned, a Class A network can support many more hosts than a Class C network.
You can determine which class any IP address is in by examining the first 4 bits of the IP address.
Class A addresses begin with 0xxx, or 1 to 126 decimal.
Class B addresses begin with 10xx, or 128 to 191 decimal.
Class C addresses begin with 110x, or 192 to 223 decimal.
Class D addresses begin with 1110, or 224 to 239 decimal.
Class E addresses begin with 1111, or 240 to 254 decimal.
Addresses beginning with 01111111, or 127 decimal, are reserved for loopback and for internal testing on a local machine. [You can test this: you should always be able to ping 127.0.0.1, which points to yourself] Class D addresses are reserved for multicasting. Class E addresses are reserved for future use. They should not be used for host addresses.
Loopback
Routers use the network address in the forwarding of data. Also, Hosts can only communicate directly with devices using the same network address.
Broadcast allows a message to be sent to all devices on a network
IP addresses are unique. No two machines can have the same IP number. IP addresses are also global and standardized.All machines connected to the Internet agree to use the same scheme for establishing an address.
