SUB:IP ADDRESS AND SUBNETTING

CLICKTECHSOLUTION.COM

THIS TOPIC WILL COVER IN EIGHT PHASES.

1. INTRODUCTION

2. NECESSITY

3. DEFINITION

4. CLASSES OF IP ADDRESS

5. PUBLIC AND PRIVATE IP ADDRESS

6. SUBNETTING

7. TYPES OF SUBNETTING

8. SUM-UP CLICKTECHSOLUTION.COM

INTRODUCTION OF IP

IP (Internet Protocol) is a routed protocol and it is working in layer-3(network layer).The routed protocols will be encapsulated data in the form of packets and is send out from the source to destination using best path that is given by the routing protocols.The routing protocols are used in routers(layer-3) .

There are two types of IP Addressing

1. IP Version4

2. IP Version6


OR

An IP address consists of four so-called octets separated by dots. The octet is a binary number of eight digits, which equals the decimal numbers from 0 to 255. To make IP addresses more easy to read and write, they are often expressed as four decimal numbers, each separated by a dot. This format is called "dotted-decimal notation".

In a local area network based on TCP/IP, an IP address must be assigned to each host (computer or device) in the network. The IP address must be unique to each host.


Every computer system and device connected to the Internet is located by an IP address. The current system of distributing IP addresses is called IPv4. This system assigns each computer a 32-bit numeric address, such as 120.121.123.124. However, with the growth of computers connected to the Internet, the number of available IP addresses are predicted to run out in only a few years. This is why IPv6 was introduced.

IPv6, also called IPng (or IP Next Generation), is the next planned version of the IP address system. While IPv4 uses 32-bit addresses, IPv6 uses 128-bit addresses, which increases the number of possible addresses by an exponential amount. For example, IPv4 allows 4,294,967,296 addresses to be used (2^32). IPv6 allows for over 340,000,000,000,000,000,000,000,000,000,000,000,000 IP addresses. That should be enough to last awhile.


http://www.techterms.com/definition/ipaddress

http://www.techterms.com/definition/ipv4

Because IPv6 allows for substantially more IP addresses than IPv4, the addresses themselves are more complex. They are typically written in this format:

hhhh:hhhh:hhhh:hhhh:hhhh:hhhh:hhhh:hhhh

Each "hhhh" section consists of a four-digit hexadecimal number, which means each digit can be from 0 to 9 and from A to F. An example IPv6 address may look like this:

F704:0000:0000:0000:3458:79A2:D08B:4320

Because IPv6 addresses are so complex, the new system also adds extra security to computers connected to the Internet. Since there are so may IP address possibilities, it is nearly impossible to guess the IP address of another computer. While most computer systems today support IPv6, the new Internet procotol has yet to be fully implemented. During this transitional process, computers are often assigned both an IPv4 and an IPv6 address. By 2008, the U.S. government has mandated that all government systems use IPv6 addresses, which should help move the transition along.


http://www.techterms.com/definition/hexadecimal

WHEN WE ARE CONNECTING TWO OR MORE COMPUTERS TOGETHER , THEN THEY CAN COMMUNICATE EACH OTHER BY USING IP ADDRESS ON EACH MACHINE.THEY CAN NOT COMMUNICATE BY USING PHYSICAL ADDRESS. THE ARP (ADDRESS RESOLUTION PROTOCOL) WILL CONVERT THIS IP ADDRESS (LOGICAL ADDRESS) IN TO MAC ADDRESS (PHYSICAL ADDRESS).THE IP ADDRESS IS A SOFTWARE ADDRESS NOT HARDWARE ADDRESS.

PC 110.0.0.1

PC210.0.0.2

SWITCH


Definition of IP Version4

It is a 32 bit binary number divided in to 4 octets ,per octets 8 bits and converted in to decimal form.The IP address is a logical address which is used to assign each and evey pc on a network.

8 BIT 8BIT 8 BIT 8 BIT

IP Version6It is in hexadecimal form and it is 128 bit address. This version is currently implemented.

OCTET 1 OCTET 2 OCTET 3 OCTET 4


Classes of IP addresses In order to provide the flexibility required to support differently sized networks, IP addresses come in three classes, A, B, and C. Every class fixes the boundary between the network portion and the host portion of the IP address at a different point. This makes them appropriate for different size networks.

Class C addresses allow 254 hosts per network and are typically used by smaller and middle-sized companies. Class B networks allow a maximum of 16,384 hosts, while Class A networks allow more than 16 million hosts. As a consequence, Class A networks are only used by really large organisations.Calculating the number of possible hosts requires a closer look at the IP classes in their binary form. (The binary system is a base-2 number system, just like the base-10 number system is known as the decimal number system). It is done as follows:


In a Class C network only the last octet is used to designate the hosts. The maximum decimal number that you can write using eight bits is 256 (28). The host calculation now requires that 2 is subtracted, because two host addresses must be reserved for a network address and a broadcast address (for a further explanation of network and broadcast addresses, see the section on ‘Subnets’). Ergo the maximum number of hosts on a Class C network is 256-2=254.

A class B network allows a maximum of 16,384 hosts (216-2) per network (two octets designate the hosts). A class A network allows up to 16,777,214 (224-2) hosts per network (three octets are used to designate the hosts).


CLASSES OF IP ADDRESS1. CLASS A

Range:- 1 to 126

It is designed for very large networks.

In this the first bit 0 in the first octet is reserved.So the address

from 0 to 127, but the 0 condition is not possible also 127 is used

as loop back address and it is used for checking of TCP/IP table

of system.

So the range is from 1 to 126.

network host host host

0 0000000::

0 1111111


2. CLASS B

Range: 128 to 191

It is designed for medium sized networks.

In this the first two bits in the first octet is reserved, so the address is from 128 to 191.

network network host host

10 000000::

10 111111


3. CLASS: C

Range: 192 to 223

It is designed for large networks

In this the first three bits in the first octet is reserved, so the address is from 192 to 223.

network network network host

110 00000::

110 11111


CLASS : D

Range: 224 to 239

These are multicast addresses.It requires specialised devices for multicasting like routers.In normal network computers ,it will not accepts class D addresses.It is also not available in market.

CLASS :E

Range : 240 to 255

It is used for scientific pupose.It is reserved by the government.


PUBLIC AND PRIVATE IP ADDRESS

PUBLIC IP ADDRESS

These are those address that we have to purchase from the service provider (ISP).

PRIVATE IP ADDRESS

No need to purchase these address.

Ranges of private IP address

Class A: 10.0.0.0-10.255.255.255

Class B: 172.16.0.0-172.31.255.255

Class C: 192.168.0.0-192.168.255.255


SUBNETTINGDEFINITION

It is a technique in which larger network is divided in to smaller sub networks , so that those sub networks will not communicate with each other.

OR

The process of converting host bits in to network bit is called sub netting.

Types of Sub -netting

There are two types of subnetting

1. Network based sub -netting

2. Host based sub -nettingCLICKTECHSOLUTION.COM

Subnetmask:-

A subnet mask is a 32 bit value, that distinguishes the network ID portion of the IP address from the host ID portion of the Ip address.

Default Subnetmask:-

ClassA:- 255.0.0.0, This is because ther is only 8 network bits.

ClassB:- 255.255.0.0, This is because there is 16 network bits.

ClassC:- 255.255.255.0, This is because there is 24 network bits.


Network based subnetting

In this we are sub -netting according to the requirement of subnets.For

Example:- Given a N/W ID – 40.0.0.0

Default subnet Mask- 255.0.0.0

Requirement- 10 Subnets ?

SolutionThe formula used is, 2 power N > Required number of subnets.2 power 4 >10, the required number of subnet is 10.Therefore N=4, it means taking 4 bits from host side in to network side.New subnet mask(NSM)= 255.11110000.00000000.00000000

= 255.240.0.0Block Size= 256-240=16 ORThe number of 0 bits remaining in that octet, that is 42 power 4 = 16Network ID:- 40.0.0.0


40. 0 . 0 . 0, subnet no140.16 . 0 . 0, subnet no240. 32 . 0 . 0, subnet no340. 48 . 0 . 0, subnet no440. 64 . 0 . 0, subnet no540. 80 . 0 . 0, subnet no640. 96 . 0 . 0, subnet no740.112. 0 . 0, subnet no840.128. 0 . 0, subnet no940.144. 0 . 0, subnet no1040.160. 0 . 0, subnet no1140.176. 0 . 0, subnet no1240.192. 0 . 0, subnet no1340.208. 0 . 0, subnet no1440.224. 0 . 0, subnet no 1540.240. 0 . 0, subnet no 16In this total sunets is 16, but we requires only 10.So we can select any 10.CLICKTECHSOLUTION.COM

ExampleGiven an IP-100.100.100.100Default Subnetmask-255.0.0.0Requirement - 5 subnet ?

Solution2 power 3 > 5So, N= 3New subnetmask- 255.11100000.00000000.00000000 = 255.224.0.0Block size = 256-224=32OR2 power 5 =32


Network ID:- To get the network ID perform the logical AND operation between the given IP and default subnetmask.

100.100.100.100255. 0 . 0 . 0

That is,01100100 . 01100100 . 01100100 . 0110010011111111 . 00000000 . 00000000 . 0000000001100100 . 00000000 . 00000000 . 00000000

That is, 100. 0. 0. 0, subnet no1 100.32. 0. 0, subnet no2 100.64. 0. 0, subnet no3 100.96. 0. 0, subnet no4 100.128.0.0, subnet no5 100.160.0.0, subnet no6 100.192.0.0, subnet no7 100.224.0.0, subnet no8


1. Total number of subnets ?2 power 3 = 8, that is the total number of bits converted from 0 to 1 in NSM.

2. Total number of hosts ?2 power 21 =2097152, that is total number of bits still 0 in all octets in NSM.

3. Total valid hosts ?Total number of valid hosts = Total hosts - 2 That is 2097152 - 2=2097150(reserver for nerwork address and broad cast address

4. Given IP belongs to which subnet ?To get this perform the logical AND operation between the given IP and New subnet mask (NSM)01100100 . 01100100 . 01100100 . 0110010011111111 . 11100000 . 00000000 . 0000000001100100 . 01100000 . 00000000 . 00000000That is, 100.96.0.0That means the given IP belongs to 4th subnet.


5. 1st and last valid IP of 5th subnet ?1st valid IP- 100.128.0.1Last valid IP-100.159.255.254

6. Last valid IP of last subnet ?Last valid IP-100.255.255.254


2. HOST BASED SUBNETTING

In host based subnetting , we are subnetting according to the requirement of hosts per subnets.

Example200.200.200.200/24Requires 10 hosts per subnetsSubnetmask-255.255.255.0 ?

SolutionNetwork ID- 200.200.200.0, That is logical AND operation between given IP and Default subnetmask.The formula is 2 power N - 2 > Required hosts per subnets.2 power 4 - 2>10That is N = 4, That means leave last 4 bits as zero in host side.New subnetmask (NSM):-255.255.255.1111 0000That is 255.255.255.240Block size256-240 =16


200.200.200.0, first subnet200.200.200.16200.200.200.32 : : : : :200.200.200.240, last subnet

1. Total number of subnets ?2 power 4 =16, That is total number of bits converted from 0 to 1 in NSM

2. Total Hosts ?2 power 4 = 16, That is total number of bits still 0 in in all octets in NSM

3. Valid number of hosts ?Total hosts-2, That is 16-2= 14CLICKTECHSOLUTION.COM

4. Given IP belongs to which subnet ?200.200.200.200255.255.255.240

200.200.200.192, That is logical AND operation between given IP and NSM.The given IP belongs to 13th subnet, That is the logical AND operation between given IP and NSM.



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SUB:IP ADDRESS AND SUBNETTING