An Internet Protocol address (IP address) is a numerical label assigned to each device connected to a computer network that uses the Internet Protocol for communication.

An IP address serves two main functions:

1.Host or Network interface identification
2.Location addressing.

There are two versions of IP

1. Internet Protocol version 4 (IPv4)
2. Internet Protocol version 6 (IPv6)

Internet Protocol version 4 (IPv4) defines an IP address as a 32-bit number. However, because of the growth of the Internet and the depletion of available IPv4 addresses, a new version of IP (IPv6), using 128 bits for the IP address, was standardized in 1998.

IPv4 addresses are usually represented in dot-decimal notation, consisting of four decimal numbers, each ranging from 0 to 255, separated by dots, e.g., 172.16.254.1. Each part represents a group of 8 bits (an octet) of the address.

Classes of IP


Static Vs dynamic IP addresses

 IP addresses are assigned in two different ways. They may be dynamically assigned (they can change automatically) or statically assigned (they are intended not to change, and must be changed manually).

Most home networks use dynamic allocation. Your router uses DHCP (Dynamic Host Configuration Protocol) to temporarily assign, or "lease," an IP address to your device.

After a period of time, this lease "expires," and the router renews your old address or assigns you a new one depending on the router configuration.


Subnet and Subnet Mask

 Dividing an IP network into blocks of logical addresses is known as subnetting.

A subnet mask is data used for bitwise operations on a network of IP addresses that is divided into two or more groups.

Subnetting can improve security and help to balance overall network traffic.

Every IP address has a corresponding subnet mask. The subnet mask specifies the range of the IP addresses in a group. The subnet mask looks a lot like an IP address. It is made up of four eight-bit numbers separated by periods. These numbers once again range from 0 to 255.

A common example of a subnet mask for Class C IP addresses is 255.255.255.0, the default subnet mask for many computers and network routers. When applied to subnet, a subnet mask shows the routing prefix.


IP Conflict

 IP address conflict occurs when two devices on the same local physical or wireless network claim to have the same IP address. The second assignment of an address generally stops the IP functionality of one or both of the devices.  Many modern operating systems notify the administrator of IP address conflicts.




Default Gateway

 A default gateway serves as an access point or IP router that a networked computer uses to send information to a computer in another network or the internet.

 In a home or small office environment, the default gateway is a device, such as a DSL router or cable router, that connects the local network to the Internet.

 Various utility software can show the default gateway. On Windows, ipconfig may be used, while on Linux systems, netstat may be used


Preferred DNS Server

The computer on which DNS software runs is called a DNS server. Anytime your computer or its software does not know what IP address goes with a specific domain name especially you are searching on internet (Eg: www.google.com), it requests that information from your preferred DNS server.

If your preferred DNS server is unavailable, your computer requests the same information from the alternate DNS server. If both servers are unavailable, your computer fails to accomplish the things you are trying to do over the Internet.

Your home router is likely set by default to use your ISP's DNS servers. Also there are a number of third-party DNS servers available as well. Two examples are  OpenDNS (208.67.220.220 and 208.67.222.222) and Google Public DNS (8.8.8.8 and 8.8.4.4)

How to Set IP in Windows

Step 1: Press Windows Key +R 
Enter ncpa.cpl

Step 2: Right Click on Network Adapter and Select Properties

STEP 3: Select TCP/IP V4 and Select Properties



STEP 5: You can see a Window like this & Assign IP address and other values


Diagnostic Tools

Computer operating systems provide various diagnostic tools to examine network interfaces and address configuration. Microsoft Windows provides the command-line interface tools ipconfig and netsh and users of Linux systems may use ifconfig, netstat, route, lanstat, fstat, and iproute2 utilities to accomplish the task.

Tip:

 What is a 255.255 255.0 subnet? 

 A class C network would have a subnet mask of 255.255.255.0 which means that 24 bits are used for the network. In CIDR notation this is designated by a /24 following the IP address. So: IP address 192.168.1.168 subnet mask 255.255.255.0 is written as: 192.168.1.168/24 in CIDR notation.

What is CIDR?

Classless Inter-Domain Routing (CIDR is a method for allocating IP addresses and IP routing.
DAY 1 IP ADDRESS

IP address Assignment



An Internet Protocol address (IP address) is a numerical label assigned to each device connected to a computer network that uses the Internet Protocol for communication.

An IP address serves two main functions:

1.Host or Network interface identification
2.Location addressing.

There are two versions of IP

1. Internet Protocol version 4 (IPv4)
2. Internet Protocol version 6 (IPv6)

Internet Protocol version 4 (IPv4) defines an IP address as a 32-bit number. However, because of the growth of the Internet and the depletion of available IPv4 addresses, a new version of IP (IPv6), using 128 bits for the IP address, was standardized in 1998.

IPv4 addresses are usually represented in dot-decimal notation, consisting of four decimal numbers, each ranging from 0 to 255, separated by dots, e.g., 172.16.254.1. Each part represents a group of 8 bits (an octet) of the address.

Classes of IP


Static Vs dynamic IP addresses

 IP addresses are assigned in two different ways. They may be dynamically assigned (they can change automatically) or statically assigned (they are intended not to change, and must be changed manually).

Most home networks use dynamic allocation. Your router uses DHCP (Dynamic Host Configuration Protocol) to temporarily assign, or "lease," an IP address to your device.

After a period of time, this lease "expires," and the router renews your old address or assigns you a new one depending on the router configuration.


Subnet and Subnet Mask

 Dividing an IP network into blocks of logical addresses is known as subnetting.

A subnet mask is data used for bitwise operations on a network of IP addresses that is divided into two or more groups.

Subnetting can improve security and help to balance overall network traffic.

Every IP address has a corresponding subnet mask. The subnet mask specifies the range of the IP addresses in a group. The subnet mask looks a lot like an IP address. It is made up of four eight-bit numbers separated by periods. These numbers once again range from 0 to 255.

A common example of a subnet mask for Class C IP addresses is 255.255.255.0, the default subnet mask for many computers and network routers. When applied to subnet, a subnet mask shows the routing prefix.


IP Conflict

 IP address conflict occurs when two devices on the same local physical or wireless network claim to have the same IP address. The second assignment of an address generally stops the IP functionality of one or both of the devices.  Many modern operating systems notify the administrator of IP address conflicts.




Default Gateway

 A default gateway serves as an access point or IP router that a networked computer uses to send information to a computer in another network or the internet.

 In a home or small office environment, the default gateway is a device, such as a DSL router or cable router, that connects the local network to the Internet.

 Various utility software can show the default gateway. On Windows, ipconfig may be used, while on Linux systems, netstat may be used


Preferred DNS Server

The computer on which DNS software runs is called a DNS server. Anytime your computer or its software does not know what IP address goes with a specific domain name especially you are searching on internet (Eg: www.google.com), it requests that information from your preferred DNS server.

If your preferred DNS server is unavailable, your computer requests the same information from the alternate DNS server. If both servers are unavailable, your computer fails to accomplish the things you are trying to do over the Internet.

Your home router is likely set by default to use your ISP's DNS servers. Also there are a number of third-party DNS servers available as well. Two examples are  OpenDNS (208.67.220.220 and 208.67.222.222) and Google Public DNS (8.8.8.8 and 8.8.4.4)

How to Set IP in Windows

Step 1: Press Windows Key +R 
Enter ncpa.cpl

Step 2: Right Click on Network Adapter and Select Properties

STEP 3: Select TCP/IP V4 and Select Properties



STEP 5: You can see a Window like this & Assign IP address and other values


Diagnostic Tools

Computer operating systems provide various diagnostic tools to examine network interfaces and address configuration. Microsoft Windows provides the command-line interface tools ipconfig and netsh and users of Linux systems may use ifconfig, netstat, route, lanstat, fstat, and iproute2 utilities to accomplish the task.

Tip:

 What is a 255.255 255.0 subnet? 

 A class C network would have a subnet mask of 255.255.255.0 which means that 24 bits are used for the network. In CIDR notation this is designated by a /24 following the IP address. So: IP address 192.168.1.168 subnet mask 255.255.255.0 is written as: 192.168.1.168/24 in CIDR notation.

What is CIDR?

Classless Inter-Domain Routing (CIDR is a method for allocating IP addresses and IP routing.