Addresses are essential for virtually everything we do on the Internet. The IP in TCP/IP is a mechanism for providing addresses for computers on the Internet. Internet addresses have two forms:
The following can be a typical person understandable address on Internet:
VWW @ ****.com
VWW is an username which in general is the name of the Internet account. This name is same as the one, which you may use when logging into the computer on which you have your Internet account. Logging in is the process of gaining access to your account on a computer, which is shared by several users. Your Internet account is created on it.
@ Connect “who” with where:
“ **** ” is a sub domain (could be several in each could be separated by (dot). Last one is referred to a domain).
.com is a domain top or what part in – It refers to “where” part which is a country code.
http://www.microsoft.com
Where,
Domain may be an apartment complex, a town or even a country. Sub-domains may correspond to organizations such as *****. Computers termed as name servers contain database of Internets host addresses. They translate word addresses or persons understandable into numeric equivalents.
Let us see another example of Internet address,
http://www.*******.ac.in
What does it all mean? Actually to the ISP server, very little. The server wants to see something quite different. It wants to see a 32-bit number as an Internet address. Something like this equivalent decimal grouping:
198.168.45.249
The Internet addresses, known as universal resources locators (URL), are translated from one form to the other using an address resolution protocol. The first address is in the form we are most used to and that user use to access an Internet site. In this example, the address is for a website, identified by the hypertext transfer protocol (http), which controls access to web pages. Following http is a delimiter sequence,://, and identification for the World Wide Web (www).
The domain name, *******.ac follows www and identifies the general site for the web. (dot) edu is one example of a domain top, which is a broad classification of web users. Other common domain tops are:
.com for commerce and businesses .gov for government agencies .mil for military sites .org for all kinds of organizations.
Lastly, in this example is a country code, again preceded by a dot. Here we are using in for the India, which is the default country.
Addresses may be followed by sub domains separated by dots or slashes (/) as needed. These addresses are translated into a 32-bit (4 decimal numeric groups) address shown as for http:// www.*******.ac.in we will further discuss this topic in the next section.
What does it all mean? Actually to the ISP server, very little. The server wants to see something quite different. It wants to see a 32-bit number as an Internet address. Something like this equivalent decimal grouping:
198.168.45.249
The Internet addresses, known as universal resources locators (URL), are translated from one form to the other using an address resolution protocol. The first address is in the form we are most used to and that user use to access an Internet site. In this example, the address is for a website, identified by the hypertext transfer protocol (http), which controls access to web pages. Following http is a delimiter sequence,://, and identification for the World Wide Web (www).
The domain name, ****.ac follows www and identifies the general site for the web.(dot) com is one example of a domain top, which is a broad classification of web users. Other common domain tops are:
.com for commerce and businesses .gov for government agencies .mil for military sites .org for all kinds of organizations.
Lastly, in this example is a country code, again preceded by a dot. Here we are using us for the U.S, which is the default country.
Addresses may be followed by sub domains separated by dots or slashes (/) as needed. These addresses are translated into a 32-bit (4 decimal numeric groups) address shown as for http:// www.google.in we will further discuss this topic in the next ARTICLES.
Port numbers are divided into three ranges:
Well-known ports are those from 0 through 1,023.
Registered ports are those from 1,024 through 49,151.
Dynamic and private ports are those from 49,152 through 65,535.
Well-known ports, those ranging from 0 through 1,023 are where most common services on the Internet are residing. These ports are controlled and assigned by the Internet Assigned Number Authority (IANA) and on most systems can be used only by system (root) processes or by programs executed by privileged users.
- Person understandable which is expressed as words.
- Machine understandable which is expressed as numbers.
The following can be a typical person understandable address on Internet:
VWW @ ****.com
VWW is an username which in general is the name of the Internet account. This name is same as the one, which you may use when logging into the computer on which you have your Internet account. Logging in is the process of gaining access to your account on a computer, which is shared by several users. Your Internet account is created on it.
@ Connect “who” with where:
“ **** ” is a sub domain (could be several in each could be separated by (dot). Last one is referred to a domain).
.com is a domain top or what part in – It refers to “where” part which is a country code.
Structure of Internet Servers Address
The structure of an Internet server’s address keyed into a client’s software is as follows:
http://www.microsoft.com
Where,
- http is the communication protocol to be used
- www is the notation for World Wide Web
- .Microsoft is the registered domain Name associated with the IP address of an Internet Server.
- .com the server provides commercial services to clients who connect to it.
To help to speed up access, its IP address can be directly represented in form of numbers. 107.56.23.1 instead of the domain name, microsoft.com. In this case no name resolution needs to take place. An Internet address is a unique 32-bit number that is typically expressed as four 8-bit octets, with each octet separated by a period. Each of the octets can take on any number from 0 through 255.
Hosts, Domains and Sub domains
Hosts are in general, individual machines at a particular location. Resources of a host machine are normally shared and can be utilized by any user on Internet. Hosts and local networks are grouped together into domains, which then are grouped together into one larger domain. For an analogy a host computer is considered as an apartment building in a housing complex and your account is just an apartment in it.
Domain may be an apartment complex, a town or even a country. Sub-domains may correspond to organizations such as *****. Computers termed as name servers contain database of Internets host addresses. They translate word addresses or persons understandable into numeric equivalents.
Let us see another example of Internet address,
http://www.*******.ac.in
What does it all mean? Actually to the ISP server, very little. The server wants to see something quite different. It wants to see a 32-bit number as an Internet address. Something like this equivalent decimal grouping:
198.168.45.249
The Internet addresses, known as universal resources locators (URL), are translated from one form to the other using an address resolution protocol. The first address is in the form we are most used to and that user use to access an Internet site. In this example, the address is for a website, identified by the hypertext transfer protocol (http), which controls access to web pages. Following http is a delimiter sequence,://, and identification for the World Wide Web (www).
The domain name, *******.ac follows www and identifies the general site for the web. (dot) edu is one example of a domain top, which is a broad classification of web users. Other common domain tops are:
.com for commerce and businesses .gov for government agencies .mil for military sites .org for all kinds of organizations.
Lastly, in this example is a country code, again preceded by a dot. Here we are using in for the India, which is the default country.
Addresses may be followed by sub domains separated by dots or slashes (/) as needed. These addresses are translated into a 32-bit (4 decimal numeric groups) address shown as for http:// www.*******.ac.in we will further discuss this topic in the next section.
What does it all mean? Actually to the ISP server, very little. The server wants to see something quite different. It wants to see a 32-bit number as an Internet address. Something like this equivalent decimal grouping:
198.168.45.249
The Internet addresses, known as universal resources locators (URL), are translated from one form to the other using an address resolution protocol. The first address is in the form we are most used to and that user use to access an Internet site. In this example, the address is for a website, identified by the hypertext transfer protocol (http), which controls access to web pages. Following http is a delimiter sequence,://, and identification for the World Wide Web (www).
The domain name, ****.ac follows www and identifies the general site for the web.(dot) com is one example of a domain top, which is a broad classification of web users. Other common domain tops are:
.com for commerce and businesses .gov for government agencies .mil for military sites .org for all kinds of organizations.
Lastly, in this example is a country code, again preceded by a dot. Here we are using us for the U.S, which is the default country.
Addresses may be followed by sub domains separated by dots or slashes (/) as needed. These addresses are translated into a 32-bit (4 decimal numeric groups) address shown as for http:// www.google.in we will further discuss this topic in the next ARTICLES.
Address Space
Internet addresses are divided into five different types of classes. The classes were designated A through E. class A address space allows a small number of networks but a large number of machines, while class C allows for a large number of networks but a relatively small number of machines per network. The following figure lists five address classes used in classical network addresses. Regardless of the class of address space assigned, organizations assigned a particular class of address will not utilize the entire address space provided. This is especially in the case of class A and Class B addresses allocation schemes.
Ports
A port is an additional 16-bit number that uniquely identifies the particular service on any given machine on the Internet. Port numbers are 16 bit wide, therefore each computer on the Internet has a maximum number of 216 or 65,536 ports. The particular application is identified by its unique port number in the same way that a specific television station has a unique channel number.
Port numbers are divided into three ranges:
Well-known ports are those from 0 through 1,023.
Registered ports are those from 1,024 through 49,151.
Dynamic and private ports are those from 49,152 through 65,535.
Well-known ports, those ranging from 0 through 1,023 are where most common services on the Internet are residing. These ports are controlled and assigned by the Internet Assigned Number Authority (IANA) and on most systems can be used only by system (root) processes or by programs executed by privileged users.
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