Friday 20 July 2012

IP V4 Addressing


IP V4 addressing: -  IP addressing is procedure to calculate unique identification numbers that help you to identify any machine in the network in other words we can say ip addressing is a combination of host bit and network bit . Network bit indicate like a zip code (to identify any type of network) and host bit indicate like a street or home ( to identify any host).


Types of IP addressing:
Class full ip addressing: This addressing divides an ip address in to network and host portion along octet boundaries. Means ip addressing with standard subnet mask.
Class Less IP addressing: In this ip addressing there is no octet boundaries like class full it can fall between different network and host portion between 0 and 31 bit .
Means ip addressing without standard subnet mask in other words we can say subnetting

Types of class full ip address:

Class
Range
Network
Total No of Network
Total No of Host per Network
A
0 to 127
Total Network:
0.0.0.0 To 127.255.255.255
Valid Network Range:
1.0.0.0 To 126.255.255.255
Useful Valid Network Range:
1.0.0.1 To 126.255.255.254
Loopback Address Range:
127.0.0.0 To 127.255.255.255
Useful Loopback Range:
127.0.0.1 To 127.255.255.254
Reserved for local identification
  0.0.0.1 To  0.255.255.254

Valid Network = 27 -2= 126
(27=128-2=126)

Total Host :
 224 =16777216
Valid Host:
16777216-2 =16777214 (Minus two ip are First ip of network is  subnet zero  last ip of network is broadcast ip)
B
128 to 191
Total Valid Network:
128.0.0.0 To 191.255.255.255
Useful Network Range:
128.0.0.1 To 191.255.255.254
Valid Network =
214 = 16,384
Total Host :
 216 =65536
Valid Host:
65536-2 =65534 (Minus two ip are First ip of network is  subnet zero  last ip of network is broadcast ip)
C
192 to 223
Total Valid Network:
192.0.0.0 To 223.255.255.255
Useful Network Range:
192.0.0.1 To 223.255.255.254
Valid Network =
221 = 2,097,152
Total Host :
 28 =256
Valid Host:
256-2 =254
(Minus two ip are First ip of network is  subnet zero last ip of network is broadcast ip)
D
224 to 239
Total Valid Network:
224.0.0.0 To 239.255.255.255
Useful Network Range:
224.0.0.1 To 239.255.255.254
28 multicast address bits

E
240 to 255
Total Valid Network:
240.0.0.0 To 255.255.255.254

28 reserved address bits Reserved for experimental use





CLASS A Definition: Address range is 0 to 127
NETWORK 8 BIT
HOST
8 BIT
HOST
8 BIT
HOST
8 BIT

To know why class a address range is 0 to 127: In class A always First bit is OFF In network octet as below describe:
 0 OFF BIT
 1 ON BIT
   1        2        3       4       5      6     7     8
  128     64      32     16     8      4     2     1
  0         1        1       1       1      1     1     1
  27 +   26 + 25 +  24 +  23 + 22 + 21 +  20   = 255-128 = 127

NETWORK 8 BIT
HOST
8 BIT
HOST
8 BIT
HOST
8 BIT

 0nnnnnnn hhhhhhhh hhhhhhhh hhhhhhhh
Always first bit is off in class a network octec and off bit is not countable so balance network bit are 7; host bits are 24
21   22   23   24   25   26   27
2    4     8    16   32   64  128
27=128 total no. of network

Total no. of network in class A: 27=128 (2*2*2*2*2*2*2)
Total no of network range: 0.0.0.0 To 127.255.255.255


Valid Network = 27-2= 126 (27=128-2=126)
Valid Network Range: 1.0.0.0 To 126.255.255.255
Useful Valid Network Range: 1.0.0.1 To 126.255.255.254
You will notice that 2 has been subtracted for valid network. This is because two of the class A network IDs 0 and 127 are reserved.
0.0.0.0/8 reserved for - Local Identification
127.0.0.0/8 reserved for - Loopback


Loop back: Class a contain loop back address it is use for testing the transmission or transportation in infrastructure. Loopback ip use for testing purpose to TCP/IP stack (services) are success fully installed or not.
Loopback Address Range: 127.0.0.0 To 127.255.255.255
Useful Loopback Range: 127.0.0.1 To 127.255.255.254


Total Host per Network = 224-2 =16777214
Here we have Minus two ip are First ip is 1.0.0.0 it’s called subnet zero and  last ip is 127.255.255.255 its  broadcast ip
  21   22   23   24   25   26   27    28       29     210     211     212        213      214  -  - - 224
2    4     8    16   32   64 128 256   512  1024  2048  4096  8192  16384 - - -16777216

/8 network 0.0.0.0 is reserved for use as the default route

CLASS A PRIVATE IP ADDRESS:
Ip range: 10.0.0.0 – 10.255.255.254
No. of address : 255 16,777,216
Subnet mask: 10.0.0.0/8 (255.0.0.0)
Host id size : 24 bits

Addressing procedure:
1.0.0.0
1.0.0.1
!
!
1.0.0.255
1.0.1.0
1.0.1.1
!
!
1.0.255.255
1.1.0.0
1.1.0.1
!
!
1.255.255.255
2.0.0.0
2.0.0.1
!
!
127.255.255.255


CLASS B Definition: Address range is 128 to 191
NETWORK 8 BIT
NETWORK 8 BIT
HOST
8 BIT
HOST
8 BIT

To know why class b address range is 128 to 191: In class b always second bit is OFF In each network octet as below describe:
 0 OFF BIT
1 ON BIT
   1        2        3       4       5      6     7     8
  128     64      32     16     8      4     2     1
  1        0        1       1       1      1     1     1
  27 +   26 + 25 +  24 +  23 + 22 + 21 +  20   = 255-64 = 191

NETWORK 8 BIT
NETWORK 8 BIT
HOST
8 BIT
HOST
8 BIT

n0nnnnnn n0nnnnnn hhhhhhhh hhhhhhhh
Always second bit is off in class b network octet and off bit is not countable so balance network bit are 14; host bits are 16
  21   22   23   24   25   26   27    28       29     210     211     212        213      214
2    4     8    16   32   64 128 256   512  1024  2048  4096  8192  16384
214=16384 total no. of network

Total no of network in class B: 214=16384 (128 to 191)
Total Valid Network: 128.0.0.0 To 191.255.255.255
Useful Network Range: 128.0.0.1 To 191.255.255.254


Total Host per Network = 216-2 =65536
Here we have Minus two ip are First ip is 128.0.0.0 it’s called subnet zero and  last ip is 191.255.255.255 its  broadcast ip
  21   22   23   24   25   26   27    28       29     210     211     212        213      214  -  - - 216
2    4     8    16   32   64 128 256   512  1024  2048  4096  8192  16384 - - -65536


CLASS B PRIVATE IP ADDRESS:
Ip range: 172.16.0.0 – 172.31.255.255.
No. of address : 1,048,576
Subnet mask: 172.16.0.0/12 (255.240.0.0)
Host id size : 20 bits


Addressing procedure:
128.0.0.0
128.0.0.1
!
!
128.0.0.255
128.0.1.0
128.0.1.1
!
!
128.0.255.255
128.1.0.0
128.1.0.1
!
!
128.255.255.255
129.0.0.0
129.0.0.1
!
!
191.255.255.255


CLASS C Definition: Address range is 192 to 223
NETWORK 8 BIT
NETWORK 8 BIT
NETWORK 8 BIT
HOST
8 BIT

To know why class c address range is 192 to 223: In class c always third bit is OFF in each Network octet as below describe:
 0 OFF BIT
1 ON BIT
   1        2        3       4       5      6     7     8
  128     64      32     16     8      4     2     1
  0         1        1       1       1      1     1     1
  27 +    26 +   25 +   24 +  23 + 22 + 21 +  20   = 255-32 = 223

NETWORK 8 BIT
NETWORK 8 BIT
NETWORK 8 BIT
HOST
8 BIT

nn0nnnnn nn0nnnnn nn0nnnnn hhhhhhhh
Always third bit is off in class c network octet and off bit is not countable so balance network bit are 21; host bits are 8
  21   22   23   24   25   26   27    28       29     210     211     212        213     - -  - - 221
2    4     8    16   32   64 128 256   512  1024  2048  4096  8192   - - - - -2,097,152
221=2097152 total no of network


Total no of network in class C: 221=2097152 (192 to 223)
Total Valid Network: 192.0.0.0 To 223.255.255.255
Useful Network Range: 192.0.0.1 To 223.255.255.254


Total Host per Network = 28-2 =254
Here we have Minus two ip are First ip is 192.0.0.0 it’s called subnet zero and  last ip is 223.255.255.255 its  broadcast ip
  21   22   23   24   25   26   27    28       
2    4     8    16   32   64 128 256 


CLASS C PRIVATE IP ADDRESS:
Ip range: 192.168.0.0 – 192.168.255.255
No. of address : 65,536
Subnet mask: 192.168.0.0/16 (255.255.0.0)
Host id size : 16 bits

Addressing procedure:
192.0.0.0
192.0.0.1
!
!
192.0.0.255
192.0.1.0
192.0.1.1
!
!
192.0.255.255
192.1.0.0
192.1.0.1
!
!
192.255.255.255
193.0.0.0
193.0.0.1
!
!
223.255.255.255

CLASS d Definition: Class D is use for multicast purpose First four bits are off ; 28 multicast address bits. Multicast is useful in certain circumstances, however, especially as a more efficient alternative to broadcasting. The “classful” IP addressing scheme sets aside a full one-sixteenth of the address space for multicast addresses: Class D. Multicast addresses are identified by the pattern “1110” in the first four bits, which corresponds to a first octet of 224 to 239. So, the full range of multicast addresses is from 224.0.0.0 to 239.255.255.255. Since multicast addresses represent a group of IP devices (sometimes called a host group) they can only be used as the destination of a datagram; never the source. The 28 bits after the leading “1110” in the IP address define the multicast group address. The size of the Class D multicast address space is therefore 228 or 268,435,456 multicast groups. There is no substructure that defines the use of these 28 bits; there is no specific concept of a network ID and host ID as in classes A, B and C. However, certain portions of the address space are set aside for specific uses.

Range Start Address
Range End Address
Description
224.0.0.0
224.0.0.255
Reserved for special “well-known” multicast addresses.
224.0.1.0
238.255.255.255
Globally-scoped (Internet-wide) multicast addresses.
239.0.0.0
239.255.255.255
Administratively-scoped (local) multicast addresses.

Note: As with the other IP address classes, the entire 32 bits of the address is always used; we are just only interested in the least-significant 28 bits because the upper four bits never change.



IP multicast protocols
§  Multicast BGP (MBGP)
§  Multicast DNS (mDNS)

CLASS D Definition: Address range is 224 to 239
8 BIT
8 BIT
8 BIT
8 BIT

In class d no host bit and no network bit total bits of ip address 28 bits are reserved in class d first four bits are OFF as below describe:
0000nnnn nnnnnnnn nnnnnnnn nnnnnnnn
In class d total no of network=228
  21   22   23   24   25   26   27    28       29     210     211     212        213     - -  - - 228
2    4     8    16   32   64 128 256   512  1024  2048  4096  8192   - - - - -------

Class D have no subnet mask

CLASS E Definition: Class E Reserved for experimental use
First four bits are off and 28 reserved address bits
Class E have no subnet mask
Class E address range are
240.0.0.0
255.255.255.255
Address range is 240 to 255
8 BIT
8 BIT
8 BIT
8 BIT

In class d no host bit and no network bit total bits of ip address 28 bits are reserved in class d first four bits are OFF as below describe:
0000nnnn nnnnnnnn nnnnnnnn nnnnnnnn
In class d total no of network=228
  21   22   23   24   25   26   27    28       29     210     211     212        213     - -  - - 228
2    4     8    16   32   64 128 256   512  1024  2048  4096  8192   - - - - -------

Classless IP Addressing:
Classless addressing system is also known as CIDR(Classless Inter-Domain Routing).Classless addressing is a way to allocate and specify the Internet addresses used in inter-domain routing more flexibly than with the original system of Internet Protocol (IP) address classes. Classful addressing divides an IP address into the Network and Host portions along octet boundaries. Classless addressing uses a variable number of bits for the network and host portions of the address. Classless addressing treats the IP address as a 32 bit stream of ones and zeroes, where the boundary between network and host portions can fall anywhere between bit 0 and bit 31. Classless routing protocols do send the subnet mask with their updates.
Thus, Variable Length Subnet Masks (VLSMs) are allowed when using
classless routing protocols.
Examples of classful routing protocols include RIPv1 and IGRP.
Examples of classless routing protocols include RIPv2, EIGRP, OSPF, and
IS-IS. Classless IP address divides in two parts: Subnetting and Supernetting

IP V4 SUBNETTING: Subnetting is a logical procedure of the dividing large no of network into smaller segment.
The two types of subnetting are:
  1. Static length subnet mask(fixed-length subnet mask (FLSM))
  2. Variable length subnet mask (VLSM)
Static Length' subnetting
If all the subnetworks in a single network use the same subnet mask, it is called as 'Static Length' subnetting.
In FLSM If address starts with 195.3.2.1/26, then whole network will belong to same subnetmask
and we can't assign as another subnet  like 197.22.75.96/28
Variable Lenght Subnet Mask (VLSM)
Variable Length Subnet Masking - VLSM - is a technique that allows network administrators to divide an IP address into different subnets sizes, unlike simple same-size Subnetting (FLSM).
The VLSM diagram below:


Supernetting:

Supernetting is the process of combining several IP networks with a common network prefix which have a common Classless Inter-Domain Routing (CIDR) routing prefix. Suppernetting is also called route aggregation or route summarization.

Supernetting was introduced as a solution to the problem of increasing size in routing tables. Supernetting also simplifies the routing process. For example, the subnetworks 192.60.2.0/24 and 192.60.3.0/24 can be combined in to the supernetwork denoted by 192.60.2.0/23. In the supernet, the first 23 bits are the network part of the address and the other 9 bits are used as the host identifier. So, one address will represent several small networks and this would reduce the number of entries that should be included in the routing table. Typically, supernetting is used for class C IP addresses (addresses beginning with 192 to 223 in decimal), and most of the routing protocols support supernetting. Examples of such protocols are Border Gateway Protocol (BGP) and Open Shortest Path First (OSPF). But, protocols such as Exterior Gateway Protocol (EGP) and the Routing Information Protocol (RIP) do not support supernetting.










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