IP Addressing Scheme is the most popular way of assigning the IP address to the devices connected to the internet where, these IP’s are classified into their respective classes for accurate identification of devices within the network. For the stability of the system, the IP is divided into two different types such as network id and host id. In this, network id is utilised for identification of the network and host id is utilised for the identification of the devices.
It is the essential component on which networking architecture is made and cannot run without its absence. IP address are assigned to the devices with the unique number which is used for sending the messages to the computers even existing outside the network. IP address is a type of logical address used for identifying every node which can also be changed.
States of IP Address:
IP address can be viewed in two states Static or Dynamic.
Static IP: - Static IP address is not changeable because, these IP’s are assigned by the user manually. For example, Static IP are usable with the DNS Servers.
Dynamic IP: - It is a type of temporary address assigned to the devices in the network with its proper configuration. These IP addresses are configured automatically by the DHCP servers which helps in reassigning, changing and allocating it to the devices.
Two types of addressing schemes are responsible for the IP, they are framed as below:
- Class full addressing scheme
- Classless addressing scheme
Class full Addressing Scheme
Five classes fall under the class full addressing scheme which are prefix of the IP address which was adopted as a part of IP in RFC 791.
Class Less Addressing Scheme
Sub-netting is done in the network to avoid the wastage of the IP addresses; host id bits is used as network id bits of the class full IP which defines the number of bits for masking like 192.168.1.1/30. No classes are used in this addressing scheme but addresses are granted in the blocks where size of block depends on nature and size of entry.
IP addresses deploys its two version IPv4 and IPv6 with different configuration where, only these two versions are in use in nowadays. IPv5 is not used for assigning the IP address because, it is being conserved for the live streaming.
Internet Protocol version 4 is widely used protocol for the data communication over the different networks where, it is used in switched layer network also said to be Ethernet which provides logical connection between the devices within the network for the unique identity of each devices. For example, 192.168.1.1 is the most common example of the IPv4 address.
Header for Ipv4 is framed as below:
- Version is used to identify the IP version in use
- The decimal value will always be 4
- Minimum length of IP header is 5*4 = 20 bytes
- Maximum length of IP header is 20 +40 = 60 bytes.
Type of Service
- 8-bit field is utilised for QoS (Quality of Service)
- This given field is considered as very useful in order to mark the datagram.
- Maximum length = 16 bit = 65535 bytes
- Minimum length can be calculated as 20 (20 bytes +0)
- Identification is the 16-bit field, which is utilised to identify the fragment about an IP datagram.
- Each fragmented data gram in this is assigned with similar numbers.
- DF stands for Do Not Fragment Bit
- 0 & 1 value is used.
- MF stands for More Fragment bits
- Value can be either 0 or 1
- 13-bit field is used in the fragment offset
- It indicates the fragmented datagram in the fragmented datagram
- First fragmented datagram has value of 0
IPv6 is the recent version of the IP address which also works as same as IPv4 but, differ from many properties that IPv4 cannot provide to the network. IPv6 holds 128-bit address which is also said to be hexa-representation, in addition to this addressing 3 addressing schemes are used i.e. Multicast, Unicast and Any cast. IPv6 address can be represented as ABCD:EF02:5678:PQRS:7773:R87S
Multi-cast Address: - It is being used by the multiple hosts which acquires a multicast destination address, but these hosts are not geographically together.
Unicast Address: - It has responsibility to identify a single network interface where the packet while sending is only delivered to the interface that have been identified by that address.
Any cast Address: - Group of interfaces comes under the category of any cast address. Once packet is sent to any cast address it will be delivered to the one-member interface.
- It represents the version of IP version 6
- 8 bits are divided into two parts in which 6 bits are used for Type of Service.
- The least 2 bits are used for Explicit Congestion Notification (ECN).
- This label is used to maintain the sequential flow of the packets.
- It is designed for streaming.
- This field is used to stop packet in loop.
- This field is used to find information a packet contains in its payload.
- It displays the address of originator of packet.
- It tells the arrival of the packet.
Sub netting of IP addresses
Each IP class is merged with its own default subnet mask which is used by the IP to have prefix number of networks and host/network. CIDR is responsible for the same, as it borrows bits of host IP and uses them in the network called subnet. With the help of sub netting, wastage of IP addresses can be minimised and large IP addresses can be divided into smaller networks.
It is used for masking an IP address which divides it into the network and host address where, each device allows its subnets to communicate with each other. All the network bits are assigned by 1 and host bits are assigned by 0.
Sub netting Example
One is allocated with a class A network address of 184.108.40.206. where user needs to create at least 20 networks and each network should support a maximum of 160 hosts. The two subnet masks are given below:
255.255.0.0 and or 255.255.255.0
Mask 255.255.0.0 has 8 bits for the subnet and 16 bits for the host
8 bits would provide 28=256 subnets
16 bits would provide 216= 64000 hosts
Mask 255.255.255.0 has 16 bits for the subnet and 8 bits of the host.
28 -2 hosts =254 is the hosts