Saturday, January 24, 2015

Basics of IP Addressing

IP Address 
Internet Protocol

An IP Address is a numeric identifier assigned to each Computer System. It identifies the location of the device in a network. Its a software address embedded in to a Network Interface Card (NIC).

In a IP Address it is a combination of some host & network address. It consists of 32 bits of Information. The Core function of IP is to provide logical addressing.

1 Bit : Means a one digit i.e. 1 or 0.
1 Byte : 8 Bits.

As well,
An IP address is a 32 bit, divided in to 4 sections each of 1 byte.
An IP address can be noted in different methods :-
1. Dotted Decimal
2. Binary
3. Hexa-decimal.

Example :-
IP address : 164.102.146.52
Binary Octet : 244.146.222.64
Hexadecimal : 00A4.0066.0092.0034
32 bit Binary : 10100100.01100110.10010010.00110100

NETWORK ADDRESSING:

Based upon network size, Number of Hosts, Number of Network the Network has been configured in 5 type of classes. ( A, B, C, D, E )
From smaller Network to a Large scale Network are defined in different classes as HOST & NETWORK each with 1 Byte = 8 Bits.



Range of IP Classes:

A : 0-127 : 00000000 00000000 00000000 00000000
B : 128- 191 : 10000000 00000000 00000000 00000000
C : 192-223 : 11000000 00000000 00000000 00000000
D : 224-239 : Reserved for Multicast.
E : 240-255 : Used for experiment and Research.

Basic Subnetting:

Sub-netting is fundamentally a way of splitting a TCP/IP network into smaller, more controllable pieces. 

Subnet Mask:

A subnet Mask defines a range or a portion of an IP address and is a 32 bit value.

DEFAULT SUB-NET MASKS :

A : 255.0.0.0
B : 255.255.0.0
C : 255.255.255.0

A Network can be split in to multiple smaller logical networks.
Network Mask or prefix indicates which bits to compare when making routing decisions.

PRIVATE ADDRESS CLASS :

A : 10.0.0.0 - 10.255.255.255
B : 172.16.0.0 - 172.31.255.255
C : 192.168.0.0 - 192.168.255.255

NETWORK ADDRESS WITH SLASH :

A : 8 bits of Network and 24 bits of hosts. 10.0.0.0/8
B : 16 bits of Network and 16 bits of hosts. 128.196.0.0/16
C : 24 bits of Network and 8 bits of hosts. 192.245.12.0 /24

When You plan for sub-netting, always remember one thing the Power of 2.

Why Subnetting is required?

The basic idea is that if you have an excessive amount of traffic flowing across your network, then those traffic can cause your network to run slowly. When you subnet  the network, you are splitting the network into a separate, but interconnected network. That way, most of the network traffic will be isolated to the subnet in which it originated.

-DR

Network Scanning Tools

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