"Supernetting" what's this stuff?

Supernetting or Classless Inter-Domain Routing (CIDR)

Supernetting, also called Classless Inter-Domain Routing (CIDR), is a way to aggregate multiple Internet addresses of the same class. The original Internet Protocol (IP) defines IP addresses in four major classes of address structure, Classes A through D. Each class allocates one portion of the 32-bit Internet address format to a network address and the remaining portion to the specific host machines within the network.

EXAMPLE:-

For example, suppose you want to supernet the 16 Class C networks

201.168.0.0 through 201.168.15.0 into a single Supernetted Address Range.

You would find the number 16 in the column labeled # of Networks and discover you need to supernet on 4 bits. This really means borrowing 2 bits from the bits normally reserved for the network portion of the address.

Since 201.168.0.0 is a Class C address with a Standard Subnet Mask of 255.255.255.0 we know we will be modifying the 3^rd octet (the last range normally reserved for network addresses) and using the first 4 bits for our network mask.

In binary, our 3^rd octet becomes 11110000 which is equivalent to 240 decimal. Therefore our subnet mask is 255.255.240.0.

If you look at the entire subnet mask in binary you can see how many addresses are reserved for the hosts:

 11111111.11111111.11110000.00000000

 nnnnnnnn.nnnnnnnn.nnnnHHHH.HHHHHHHH

All the positions where 0s or Hs are present represent the Host address portion. There are 12 H’s present, so 2¹²=4096 which is the same as 256*16 (the number of networks we were originally trying to combine).

For more accurate information see the following VIDEO:-

CLOCK SPEED & PROCESSOR SPEED

Clock speed vs Processor speed

‘Clock speed’ and ‘Processor speed’ are two terms used to determine the performance of a processor. Although both of them are measured in Hertz (Hz), those terms have different meanings. Processor is synchronized with a clock, and processor speed is depended on the clock speed.

Clock Speed

Clock is a device that ticks in regular intervals, and the signal it generates is a regular square pulse. This signal helps to synchronize the cycles of a processor. Generally, a crystal oscillator is used to generate this clock signal. Frequency of this oscillator is called the clock speed or clock rate. The number of square pulses within a second is the clock speed. Therefore, the clock speed is measured in Hertz (Hz).

Most digital electronic devices such as memory, Front Side Bus (FSB), are needed to be synchronized by a 

clock. Otherwise, the operation becomes unsuccessful.

Processor speed

Processor speed is the amount of cycles, which a CPU completes within a second. It is also measured in Hertz (Hz). For example, a 10Hz processor can complete 10 cycles within a second, and a 1GHz processor completes a billion cycles within a second.

Usually processor cycles are synchronized with an internal or external clock. Clock speed can be increased using a multiplier.

What is the difference between Clock Speed and Processor Speed?

1. Clock speed is the number of pulses that a crystal oscillator generates within a second, and processor speed is the number of cycles completed by a processor within a second.

2. A processor should be synchronized by a clock, and therefore, processor speed is depended on clock speed.

Let's Know TCP & IP

TCP vs IP

 TCP and IP are the first and the most important two communication protocols in the Internet Protocol Suite (which include all the communications protocols, i.e., set of rules and message formats implement to transfer data between computer systems, used for Internet and other networks). Sometimes the Internet Protocol Suite is referred to as TCP/IP due to the importance the two protocols hold. TCP belongs in the Transport Layer and IP belongs in the Internet Layer of the Internet Protocols Suite.

What is IP?

IP or the Internet Protocol is the basic protocol that makes up the Internet, as it is responsible for the addressing hosts (computers) and transportation of data packets between hosts, through a packet switched internetwork. Residing on the Internet Layer of Internet Protocol Suite, IP only carries out the task of delivering packets of data (Datagrams) from one host to another, depending on the host addresses; therefore, is considered unreliable, as Data Packets send through Internet using IP can be lost, corrupted or delivered in an unordered manner.

As the main tasks of the IP is Addressing and Routing (delivery of data packets), IP defines an addressing system that identify and give logical IP addresses or locations to hosts. IP routing is usually performed by both hosts and routers, which forwards data packets encapsulated with a header that contains information about data and destination IP address, and a body that contains data, to destination hosts.

What is TCP?

TCP or the Transmission Control Protocol, which belongs in the Transport Layer of the Internet Protocol Suit, assures reliability and the ordered delivery of information (in the form of byte streams) from one computer to another. Most of the Internet applications that require reliable and secure data transferring such as World Wide Web, E-mail, peer-to-peer file Sharing, Streaming media applications and other file transferring services, uses TCP for transmission and communication purposes.

TCP acts as an intermediate layer between application and internet layers. When an application needs to send data across Internet using IP, without directly accessing IP, application sends requests to TCP, which handles all the IP related details. If there is any packet loss, corruption or unordered data delivery is detected by TCP, it requests the data packets to be resend and re-arranges data before it is sent back to the application. TCP worries about accurate data transmission rather than fast delivery; therefore, may cause delays waiting for re-transmissions, data ordering, etc.

What is the difference between IP and TCP?

IP and TCP are two protocols that work together in reliable delivery of data over the networks, especially Internet. While IP defines rules that deliver the data from one host to another, TCP defines rules that make sure delivered data is without any loss or corruption and is delivered in an orderly manner.

The main difference between the two protocols is the layers that they reside in. TCP belongs to Transport Layer and IP belongs to Internet Layer of the Protocol Suit. In addition, while TCP gives priority to the accuracy of the data delivered, IP gives priority to the accuracy of the location of data delivery than accuracy of data.

Furthermore, IP defines a set of logical addresses referred to as IP addresses, which helps in the identification of source and destination hosts that are vital for accurate delivery as well as in maintaining data accuracy, as when corruption or loss of data occurs, the source destination must be known for re-transmission.

Read more: http://www.differencebetween.com