Skip to main content

What is an IP address?

Every machine on the Internet­ has a unique identifying number, called an IP Address. A typical IP address looks like this:
  • 216.27.61.137
To make it easier for us humans to remember, IP addresses are normally expressed in decimal format as a "dotted decimal number" like the one above. But computers communicate in binary form. Look at the same IP address in binary:
  • 11011000.00011011.00111101.10001001
The four numbers in an IP address are called octets, because they each have eight positions when viewed in binary form. If you add all the positions together, you get 32, which is why IP addresses are considered 32-bit numbers. Since each of the eight positions can have two different states (1 or 0) the total number of possible combinations per octet is 28 or 256. So each octet can contain any value between 0 and 255. Combine the four octets and you get 232 or a possible 4,294,967,296 unique values!
Out of the almost 4.3 billion possible combinations, certain values are restricted from use as typical IP addresses. For example, the IP address 0.0.0.0 is reserved for the default network and the address 255.255.255.255 is used for broadcast.

The octets serve a purpose other than simply separating the numbers. They are used to create classes of IP addresses that can be assigned to a particular business, government or other entity based on size and need. The octets are split into two sections: Net and Host. The Net section always contains the first octet. It is used to identify the network that a computer belongs to. Host (sometimes referred to as Node) identifies the actual computer on the network. The Host section always contains the last octet. There are five IP classes plus certain special addresses:
  • Default Network - The IP address of 0.0.0.0 is used for the default network.
  • Class A - This class is for very large networks, such as a major international company might have. IP addresses with a first octet from 1 to 126 are part of this class. The other three octets are used to identify each host. This means that there are 126 Class A networks each with 16,777,214 (224 -2) possible hosts for a total of 2,147,483,648 (231) unique IP addresses. Class A networks account for half of the total available IP addresses. In Class A networks, the high order bit value (the very first binary number) in the first octet is always 0.
Net
Host or Node
115.
24.53.107
  • Loopback - The IP address 127.0.0.1 is used as the loopback address. This means that it is used by the host computer to send a message back to itself. It is commonly used for troubleshooting and network testing.

Labels

Labels:

Comments

Post a Comment

Popular posts from this blog

Exp/ Imp vs. ExpDP/ ImpDP in Oracle 10g

ORACLE Export (exp) vs Datapump (expdp)    ORACLE provides two external utilities to transfer database objects from one database to another database. Traditional exports (exp /imp) are introduced before 10g. Then from 10g, ORACLE introduced datapump (expdp / impdp) as an enhancement to traditional export utility. Traditional Export (exp/ imp) This is an ORACLE database external utility, which is used to transfer database objects from one database server to another database server. It allows transferring the database objects over different platforms, different hardware and software configurations. When an export command is executed on a database, database objects are extracted with their dependency objects. That means if it extracts a table, the dependences like indexes, comments, and grants are extracted and written into an export file (binary format dump file). Following is the command to export a full database, Cmd > exp userid=username/password@exportdb_...
Post a Comment
Read more

Hi! I'm Java...

Java is a computer programming language. It enables programmers to write computer instructions using English based commands, instead of having to write in numeric codes. It’s known as a “high-level” language because it can be read and written easily by humans. Like English, Java has a set of rules that determine how the instructions are written. These rules are known as its “syntax”. Once a program has been written, the high-level instructions are translated into numeric codes that computers can understand and execute. Who Created Java? In the early nineties, Java was created by a team led by James Gosling for Sun Microsystems. It was originally designed for use on digital mobile devices, such as cell phones. However, when Java 1.0 was released to the public in 1996, its main focus had shifted to use on the Internet. It provided more interactivity with users by giving developers a way to produce animated webpages . Over the years it has evolved as a successful language for ...
1 comment
Read more

Setting up OpenGL environment for Microsoft Visual C++

Hi Friends, before starting the setting up OpenGL environment, please do the following first: 1.       Install Microsoft Visual C++ 6.0 (Comes with Ms Visual Studio 6.0) 2.       Download the file called “opengl95.exe” and “glutdlls.zip” from internet. [Just open browser-> navigate http://www.google.com -> type upper mentioned file name and search -> you will definitely find the appropriate link to download.] 3.       Run opengl95.exe file and it will be extracted and will be generated some files. Copy those files and 4.       Extract the file “glutdlls.zip” and it will also generate some more files. 5.       Now, combine all extracted files from two sources (opengl95.exe and glutdlls.zip) and place in one location. Setting up OpenGL environment for Microsoft Visual C++ With any system, you can start with a C\C++ compiler and install ...
Post a Comment
Read more