Lesson 17 IP ADDRESSING

Transcription

1 Lesson 17 IP ADDRESSING 1

2 WHAT IS IP This is the acronym for Internet Protocol, which is the one of the network layer protocols. it is primarily used to identify devices in a network to enable transfer of information from one host to another. IP v4 CLASSES There are 5 different classes of IP address as seen in the picture above. IP address classes were created to make the addresses assigned to the host manageable and to easily identify a collection of hosts called networks network 2

3 IP address are broken into 4 parts each containing 8 bits (bits are ones or zeros or binary number notations). Note these will be discussed later. The Class A Network : This uses the first part of the IP address as network and the last three as host. The Network address ranges from 1.X.X.X 127.X.X.X. Example a network has host ranging from The Class B Network : This uses the first two parts of the IP address as network and the last two as host. The Network address ranges from X.X X.X. Example a network has host ranging from The Class C Network : This uses the first three part of the IP address as network and the last part as hosts. The Network address ranges from X X. Example a network has host ranging from The Class D Network : All the address in the class D network are used as multicast addresses. A multicast address is an address used to talk to a selective groups of devices registered to receive information sent to that address. An example is mean to all routers. The address ranges from Please note multicast IP address do not have a host component are are used mainly for one way traffic like a radio station and your radio. Another example will be video streams.. The Class E Network : This is reserved for research purposes and ranges from to SPECIAL IP ADDRESSES Special IP address do exist for specific purposes or are noticed/used by different company network card/operating systems. Private IP address: IP was such a big hit due to the success and ubiquitousness of the internet. As the name implies Internet Routing Protocol was used to send data across the internet. 3

4 However, there were some who wanted to use IP address for private uses. Problem was they were not allowed to use the reserved the IP address. Thus forced the need to create sets of IP address within all the classes that could be used for Private purposes. Note the word Private here means it can not be directly used to send traffic to other devices on the internet. This enabled the creation of multiple private Networks and these IP address are called Non routable Address. The figure above depicts the addresses used by for these purposes. Public Address: This are all addresses that are not defined as private IP address. They are also called routable ip addresses Loopback Address : This is also called the host IP address, as it points to the devices itself. It is used to test services on the PC, example a web server. Link Local IP Address : This the IP address the devices is issued when all other means (manual and through DHCP) fails. In practice this IP addresses mean a IP address allocation failure. 4

5 BINARY TO DECIMAL CONVERSION If you noticed the all four parts of an IP address do not exceed 255 and are never lower than 0. The reason is due to the fact that this IP address parts are actually in binary system., but calculated/converted to the decimal notation you are used t. What is the Binary system: The Binary system is used by the computer and come in the form or ones or zeros. The lowest number in a binary is 0 and the maximum is 1. each of the one or zeros is called a bit. As defined each part or octet (means 8) has 8 bits, or 8 chances ofr the pc to chose ye or no, true or false. Calculations. Calculation of the binary system is similar to that of the decimal. In decimal once we reach 9, we put a 1 in front of the zero and continue counting. Hence the following is true in decimal means = (1 * 10 4 ) + (3 * 10 3 ) + (8 * 10 2 ) + (9 * 10 1 ) + (5 * 10 0 ) = (1* 10 * 10 * 10 * 10) + (3* 10 * 10 * 10) + (8* 10* 10) + (9* 10) + (5 *1) = (10000) + (3000) + (800) + (90) + (5 *1) same goes for converting binary to decimal = (1 * 2 4 ) + (1 * 2 3 ) + (0 * 2 2 ) + (1 * 2 1 ) + (0 * 2 0 ) 5