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

Basics of IP, ICMP

IP Internet Protocol 

IP is the internet layer. It uses each packet’s Address. It uses routing Table by which it decides where a packet is to be sent choosing its best path

An IP Header feature are as below;

• Version : it describes IP version no.
• Header length: HLEN in 32 bit
• Priority & Type of Service: It describes how the datagram should be handled.
• Total Length: Length of the packet including header & data.
• Identification: Unique IP Packet value used to differentiate fragmented packets from diff data grams.
• Flags : Specifies whether fragmentation should occur.
• Fragment offset: provides fragmentation & allows different maximum transmission unit MTUS on the internet.
• TTL : Time to Leave: TTL is set in to the packet when generated for reaching at destination within time limit. Otherwise it get Lost.
• Protocol : Port of upper layer protocol. (tcp-6 & udp-17)
• Header Check sum: CRC (Cyclic Redundancy Check Only) on header.
• Source IP Address: 32-bit IP address of Sender.
• Destination IP address: 32-bit IP address of Receiver/ Destination .
• Options: It is Used for testing [ network, debug, security].
• Data: After the IP option field is the upper layer data.

   ICMP : Internet Control Message Protocol parameters

I

Basics of Telnet and other protocols

Some useful networking protocols in brief

Telnet (Terminal Emulation):

It Allows Users from remote client system to connect or access other client system or resources, Servers. By using telnet client software one can access/log in to  the server.

SMTP (Simple Mail Transfer Protocol):

Doing the process for email delivery, message queuing , checking the message, spooling the message.

TFTP (Trivial File Transfer Protocol):

It is being used only for sending and receiving files of very small amount mean small data. It does not have directory browsing facility and it is not secure method .

FTP (FILE TRANSFER PROTOCOL):

It is the real protocol used for transfer for files. it is not just a protocol but also a programme. Most of FTP client and server software are now available to the market. It have authentication of users , allows to access the directories of files, browsing of directory, copy paste options.

It is faster than email while sending or receiving Large Files while we know some email services provide max 25 MB of data to be attached.

IMAP(Internet Message Access Protocol):

Used for making control over mails, downloading mails, Gives option for search mail with commands based on message subject, header, to mail etc. You  can store mails on mail Server. Now its being used as Version 4 and so far called IMAP4. Before IMAP there was POP ( Post Office protocol ) which was earlier used to store incoming mail but it does not allow to download mails selectively. 

SNMP(Simple Network Management protocol):

This protocol Collects & Pulls valuable network information, gathers the data of the devices connected in a network with some time intervals. This protocol also notices and alerts any events happening in a network.

version 1, 2, 3 available. v3 have more security, encryption and authenticity option.

SSH ( Secure Shell ):

It conducts a secure telnet session over a standard tcp/ip connection. And is assigned for logging in to systems, running programs on remote system, moving files from one system to another, remote command execution. Client software available freely like putty, open ssh. 

SSH CONNECTION

HTTP ( HYPERTEXT TRANSFER PROTOCOL ):

It is used to manage communications between web browser and web servers when we click on a link for any resource. It retrieves the data as per its name from different location around the world.

HTTPS ( Secure ):

 Its a Secure Protocol for HTTP and it uses secure socket layer.It enables you to do transactions online secure, whether in any log in process or for eCommerce use.

DNS:

Domain Name Service ( System ) 

It resolves Host name. DNS allows to use the domain name HOSTs to specify IP Address. It is being easy to remember than the IP Address, so it uses Alphabetic characters. Similarly the domain name converts it in to respective IP Addresses.

 After that a DNS is used to resolve a FQDN ( Fully Qualified Domain Name ).It specifies the exact location of the Domain name i.e. Host name + Domain Name. The DNS Server solves it by using the looking of DNS Table.

DHCP:

Dynamic Host Configuration Protocol

It Assigns IP Address to Hosts/clients . It allows Administration and control over a network of small or Large.

A DHCP Server provides the information as : 

•  IP Address
•  Subnet Mask
•  Domain Name
•  Default Gateway { IP Address of Router }
•  DNS Server address
•  WINS Server Address

Hence the DHCP conflict occurs in a network when there are Two same IP Address is given to two Hosts.

While assigning IP Address, It checks the availability of IP address by pinging request then resumes in the network.

Post Office Protocol (POP):

The POP protocol uses basically in email messaging. It provides the storage facility for all incoming mail. The used POP is called POP3.

Transport Layer Security (TLS):

The TLS protocol is one of the encryption protocol same as SSL (Secure Socket Layer) protocol. It enables secure online data transfer during browsing,  messaging, etc.

ARP

An Address Resolution Protocol (ARP) finds the hardware address of host from a known IP address. When IP has a datagram to send, it must inform a Network Access protocol, such as Ethernet or Token Ring, of the destination’s hardware address on the local network. ARP resolves IP addresses to Ethernet addresses.

-DR