An IP address is a unique identifier assigned to every device on a network that uses the Internet Protocol for communication. IP addresses are typically expressed as a set of four numbers , , each number contains one to three digits, with a single dot (.) separates each number or set of digits, such as 192.168.1.1.
1.How does IP address work?
IP (Internet Protocol) address is a unique numerical identifier that is assigned to every device connected to the internet. The IP address works by providing a way for data to be transmitted between different devices over the internet.
When a device connects to the internet, it is assigned an IP address by its Internet Service Provider (ISP). The IP address is typically assigned dynamically, which means it can change each time the device connects to the internet. However, it’s also possible to have a static IP address, which is an address that remains the same each time the device connects to the internet.
IP addresses are composed of four sets of numbers, separated by dots. Each set of numbers can range from 0 to 255, and the maximum value of an IP address is 255.255.255.255. The IP address is divided into two parts: the network address and the host address. The network address is used to identify the network that the device is connected to, while the host address identifies the specific device within that network.
When data is sent over the internet, it is broken down into smaller packets. Each packet contains the IP address of the device it is being sent to, as well as the IP address of the device it is being sent from. These packets are then sent over the internet and are reassembled at their destination.
The IP address is used by routers and other networking devices to route the packets to their destination. Routers use a process called routing to determine the most efficient path for the packet to take to reach its destination. The routing process takes into account the network address of the destination device, as well as the network address of the router.
In summary, IP addresses work by providing a unique identifier for each device connected to the internet. This identifier is used to route data between devices and to ensure that the data arrives at its intended destination.
2.What is Classful Addressing?
Classful addressing is a method of IP address assignment that was used in the early days of the internet. Under classful addressing, IP addresses were divided into three classes: Class A, Class B, and Class C.
Each class of IP addresses had a predetermined range of addresses that could be assigned. Class A addresses had a first octet range of 1-126, Class B addresses had a first octet range of 128-191, and Class C addresses had a first octet range of 192-223.
Classful addressing was based on the assumption that the network and host portions of an IP address were fixed, with the network portion being determined by the class of the address. For example, a Class A address would have the first octet used to identify the network, while the remaining three octets were used to identify individual hosts on that network.
Classful addressing made it easy to determine the size of a network based on the class of its IP address, but it had several limitations. One limitation was that it did not allow for efficient use of IP addresses, as the size of the network was determined by the class of the address, not the actual number of hosts on the network. This led to the waste of IP addresses, as many networks had more addresses than they actually needed.
Another limitation of classful addressing was that it did not allow for variable-length subnet masks (VLSMs). Subnetting is a method of dividing a network into smaller subnetworks to improve network performance and efficiency. With classful addressing, the network portion of an IP address was fixed based on the class of the address, so it was not possible to subnet a network further than the predetermined class boundaries.
Classful addressing has been largely replaced by classless addressing, which allows for more efficient use of IP addresses and greater flexibility in network design. Classless addressing uses variable-length subnet masks (VLSMs) to allow networks to be subdivided into smaller subnets as needed.
What is Class A Network?
In the early days of the internet, IP addresses were divided into three classes: Class A, Class B, and Class C. Class A networks are the largest of the three classes and are identified by the first octet of the IP address, which is always in the range of 1 to 126.
In a Class A network, the first octet is used to identify the network portion of the address, while the remaining three octets are used to identify individual hosts on that network. This means that a Class A network can have up to 126 networks, with each network containing up to 16,777,214 hosts.
The default subnet mask for a Class A network is 255.0.0.0, which means that the first octet is used to identify the network, and the remaining three octets are used to identify hosts. However, it is also possible to use variable-length subnet masks (VLSMs) to divide a Class A network into smaller subnets.
Class A networks are often used by large organizations or internet service providers (ISPs) that require a large number of IP addresses to connect a large number of devices to the internet. However, due to the limited number of Class A networks available, they are relatively rare compared to Class B and Class C networks.
Some examples of Class A networks include 10.0.0.0/8, 100.0.0.0/8, and 126.0.0.0/8.
What is Class B Network?
In the early days of the internet, IP addresses were divided into three classes: Class A, Class B, and Class C. Class B networks are smaller than Class A networks but larger than Class C networks and are identified by the first octet of the IP address, which is always in the range of 128 to 191.
In a Class B network, the first two octets are used to identify the network portion of the address, while the remaining two octets are used to identify individual hosts on that network. This means that a Class B network can have up to 16,384 networks, with each network containing up to 65,534 hosts.
The default subnet mask for a Class B network is 255.255.0.0, which means that the first two octets are used to identify the network, and the remaining two octets are used to identify hosts. However, it is also possible to use variable-length subnet masks (VLSMs) to divide a Class B network into smaller subnets.
Class B networks are often used by medium-sized organizations or internet service providers (ISPs) that require a moderate number of IP addresses to connect a moderate number of devices to the internet.
Some examples of Class B networks include 128.0.0.0/16, 172.16.0.0/12, and 191.0.0.0/8.
What is Class C Network ?
In the early days of the internet, IP addresses were divided into three classes: Class A, Class B, and Class C. Class C networks are the smallest of the three classes and are identified by the first octet of the IP address, which is always in the range of 192 to 223.
In a Class C network, the first three octets are used to identify the network portion of the address, while the remaining octet is used to identify individual hosts on that network. This means that a Class C network can have up to 2,097,152 networks, with each network containing up to 254 hosts.
The default subnet mask for a Class C network is 255.255.255.0, which means that the first three octets are used to identify the network, and the remaining octet is used to identify hosts. However, it is also possible to use variable-length subnet masks (VLSMs) to divide a Class C network into smaller subnets.
Class C networks are often used by small organizations or home networks that require a small number of IP addresses to connect a small number of devices to the internet.
Some examples of Class C networks include 192.0.0.0/24, 198.51.100.0/24, and 223.255.255.0/24.
What is Class D Network?
Class D network is one of the five classes of IP addresses defined by the Internet Engineering Task Force (IETF). Unlike Class A, B, and C networks, Class D addresses are not used for identifying individual hosts on a network. Instead, they are used for multicast addressing, which is a way of sending a single packet to multiple hosts on a network simultaneously.
In a Class D address, the first four bits of the first octet are always set to 1110. The remaining 28 bits can be used to specify the multicast group address. This means that Class D addresses range from 224.0.0.0 to 239.255.255.255.
Multicast addressing is used for applications such as video conferencing, online gaming, and streaming media, where the same data needs to be sent to multiple hosts simultaneously. With multicast addressing, a single packet can be sent to all hosts in a multicast group with a single transmission.
It is important to note that Class D addresses are not assigned to individual hosts or networks like Class A, B, and C addresses. Instead, they are reserved for multicast addressing and can be used by any host on a network.
Rules for Assigning Network ID:
In IPv4 addressing, there are certain rules for assigning network IDs, which help to ensure that IP addresses are assigned in a way that enables efficient routing and prevents conflicts. The rules for assigning network IDs are as follows:
- The network ID must be unique: Every network ID must be unique within the entire internet, to ensure that packets are routed correctly.
- The network ID cannot be used as a host ID: The network ID identifies the network, and cannot be used to identify individual hosts on that network. The host ID must be unique within the network.
- The network ID cannot be all zeros or all ones: All zeros and all ones are reserved for specific purposes and cannot be used as a network ID.
- The network ID cannot be in the range of private IP addresses: Private IP addresses are reserved for use within private networks and cannot be used as a network ID on the public internet.
- The network ID must be compatible with the subnet mask: The subnet mask determines how the IP address is divided into network and host portions. The network ID must be compatible with the subnet mask to ensure that packets are routed correctly.
- The network ID must be assigned by a recognized authority: Network IDs must be assigned by a recognized authority, such as the Internet Assigned Numbers Authority (IANA), to ensure that they are unique and compatible with the internet addressing system.
These rules ensure that IP addresses are assigned in a way that enables efficient routing and prevents conflicts, while also ensuring that networks are easily identifiable and can communicate with each other effectively.