CIDR (Classless Inter-Domain Routing )
Classless Inter Domain Routing (CIDR) is a method for assigning IP addresses without using the standard IP address classes like Class A, Class B or Class C. In CIDR notation, an IP address is represented as A.B.C.D /n, where "/n" is called the IP prefix or network prefix. The IP prefix identifies the number of significant bits used to identify a network.
Ex: 126.96.36.199, with subnet mask of 255.255.255.128 may be written as 188.8.131.52/25 using CIDR Notation.
1. An IP address (32 bit number, 4 bytes) consists of four octets seperated by dots. The octet is a binary number of eight digits, which equals the decimal numbers from 0 to 255.
2. IP v6 addressing
1. IPv6 address is 128 bits in length represented in hexadecimal
2. IPv6 Loopback address is 0:0:0:0:0:0:0:1, also expressed as ::1.
3. IPv6 reserves two special addresses. They are 0:0:0:0:0:0:0:0 and 0:0:0:0:0:0:0:1.
4. Three transition strategies for migration from ipv6 to ipv4 are dual stacking, 6-to-4 tunneling and NAT-PT
IPv6 address consists of 8 groups of four hexadecimal digits separated by colons and which mainly consists of 3 segments called Global Prefix which is of 48 bits, subnet part with 16 bits and Interface ID called as Host part with 64 bits. The first 3 octets constitute Global Prefix, the fourth octet constitute subnet part and the last four form the Interface ID.
a) One set of 0's in the address can be replaced by :: but this can be done only once
b) One or any number of consecutive groups of 0 value can be replaced with two colons (::)
It is a unique value associated with a network adapter. These are also known as hardware addresses or physical addresses. It contains 12-digit hexadecimal numbers (48 bits in length)
By convention, MAC addresses are usually written in one of the following two formats:
The first half of a MAC address contains the ID number of the adapter manufacturer. The second half of a MAC address represents the serial number assigned to the adapter by the manufacturer. In the example, 00:A0:C9:14:C8:29
The prefix 00A0C9 indicates the manufacturer is Intel Corporation.
The number 14C829 is the serial number assigned by the manufacturer.
It is nothing but creating networks within a network. Subnetting allows an organization with a single IP address (Class A /ClassB /ClassC) to have multiple subnetworks, thus allowing several physical networks within the organization.
Default subnet mask for Class A network: 255.0.0.0
Default subnet mask for Class B network: 255.255.0.0
Default subnet mask for Class C network: 255.255.255.0
The directed broadcast should reach all Hosts on the intended network (or subnet, if sub netted). For example, the directed broadcast address for an IP network 184.108.40.206 with default subnet mask is 220.127.116.11. This is arrived by putting all 1s for the host portion of the IP address.
Packets are sent from single source to specific destination. There is only one sender and one receiver.
It uses IP delivery methods such as Transmission Control Protocol (TCP) and User Datagram Protocol (UDP), which are session-based protocols
Examples FTP, Telnet
Packets are sent from one source to all other clients. There is only one sender and all connected clients are receivers
It is largely confined to local area network (LAN) technologies, mostly Ethernet and token ring
Packets are sent from one or more sources to set of receivers. There can be one or more senders and one or more receivers.
It is useful if a group of clients require a common set of data at the same time, or when the clients are able to receive and store (cache) common data until needed
APIP (Automatic Private IP Addressing)
APIPA (Short for Automatic Private IP Addressing), is a feature that allows DHCP clients to automatically self-configure an IP address and subnet mask when a DHCP server isn't available. When a DHCP client boots up, it first looks for a DHCP server in order to obtain an IP address and subnet mask. If the client is unable to find the information, it uses APIPA to automatically configure itself.. The IP address range is 169.254.0.1 through 169.254.255.254. The client also configures itself with a default class B subnet mask of 255.255.0.0.