Saturday, November 18, 2006

What is IP Address and Subnet Masks?


IP Address is the set of numbers which uniquely identifies the machine on a network and the network to which it is attached. IP Address identifies the machine's connection to the network but not the machine itself. When a machine's location on the network changes,the IP address also changes. TCP/IP uses this 32 bit IP Address to identify a machine on a network and the network to which it is attached.

The machine on a network is called as Host. Each TCP/IP host is identified by a unique IP Address. Internally each IP Address is separated into two parts network ID and a Host ID.

The network ID identifies a single network segment within the larger internetwork. Internetwork is a network of networks. All machines that are access to the same network have a common network ID. The host ID identifies a TCP/IP node within each network. A node may be a workstation or server or router or other TCP/IP device.

IP Addresses are four sets of 8 bits,totally 32 bits. IP Addresses are usually expressed in decimal notation instead of long binary strings. These 8 bit octets are converted to decimal numbers and separated by periods. For example 192.168.1.2 is an IP Address.

There are 5 IP Address classes. Out of these 5 three classes are used for assignment to TCP/IP nodes. They are Class A,B and C.

The IP Address class defines which bits are used for network ID and host ID parts of each address. It also defines howmany networks and hosts per network can be supported.

For example p.q.r.s represent the four octet values in any IP Address.

For Class A the value of p is 1-126. First octet p represents network ID. The remaining 3 octets q.r.s represents Host ID. Class A supports 126 networks and 16,777,214 hosts per network.

For Class B the value of p is 128-191. First two octets p.q represents network ID. The last two octets r.s represents Host ID. Class B supports 16,384 networks and 65,534 hosts per network.

For Class C the value of p is 192-223. First three octets p.q.r represents network ID. The last octet s represents Host ID. Class C supports 20,97,152 networks and 254 hosts per network.

Subnet Masks:

Subnet Mask is also a 32 bit number. Subnet Mask identifies Network ID and Host ID parts within the IP Address. Subnet Mask uses bit groups of all ones to identify the network ID and uses bit groups of all zeroes to identify the Host ID parts of an IP Address.

For example take IP Address 192.168.1.2 The value of first octet is 192. So this is Class C IP Address. p.q.r represents network ID and s represents Host ID. So for above IP address network ID is 192.168.1 and Host ID is 2.

For the above IP Address Subnet Mask number is 11111111 11111111 11111111 00000000 In decimal notation it is 255.255.255.0

For Class A IP Address Subnet mask is 255.0.0.0
For Class B IP Address Subnet mask is 255.255.0.0

Note: Articles on Windows NT,Windows 2000 Server,Windows 2003 Server will come soon on my blog under the same NETWORKING section.

What is TCP/IP Protocol?


Protocol is a pre defined set of rules. When nations conduct business between them then they follow certain rules so that everything proceeds smoothly. Similarly if one computer is communicating with another one then they both must follow a pre defined set of rules called protocol. If they follow the protocol properly then only message will be transferred from one machine to other,regardless of what type of machines they are and what operating systems they run. Communications are possible with the help of a software that can manage the protocol. That software is nothing but TCP/IP.

TCP/IP is a software based communications protocol that provides network services such as remote logins,remote file transfers, and electronic mail. It transfers information from one machine to another. It provides reliable transfer of data. TCP/IP handle errors in transmission.manage the routing of data,manage the delivery of data and control the transmission by the use of predetermined status signals. TCP/IP was designed with layers. TCP/IP responsible for assembling data passed from higher layer applications into standard packets and ensuring that the data is transferred correctly.

TCP/IP is a combination of two protocols transmission control protocol and Internet protocol. Internet protocol is responsible for moving the packets of data assembled by TCP across networks. It uses a set of unique addresses(IP Addresses)for every device on the network to determine routing and destinations. Internet protocol main tasks are addressing of datagrams of information between computers and managing the fragmentation process of these datagrams. The protocol has a formal definition of the layout of a datagram of information and the information of a header composed of information about the datagram. IP is responsible for the routing of a datagram and determines where it will be sent .

IP does not guarantee datagram's delivery. It has no reliability. It simply handles the routing of datagrams. If problem occurs IP discards the packet and generate an ICMP error message to the sender. But TCP takes the charge if problems occur. TCP provides reliable transfer of data. TCP is responsible for ensuring the transfer of a datagram from the source to the destination machine and receive acknowledge receipt of the datagram from the destination machine.

Note: Articles on Windows NT,Windows 2000 Server,Windows 2003 Server will come soon on my blog under the same NETWORKING section.

What is a Wide Area Network?


Introduction:

A set of computers and peripherals connected together by a medium is called a network. All these devices on the netwok communicate with each other through a protocol. All these devices on a netwok can be in the same room or scattered through a building or scattered in different buildings or different cities. All these devices can be separated by many miles by the use of dedicated telephone lines or microwave etc.

Peripherals are nothing but Printers,Scanners,Modems,Plotters etc.
Protocol is a predefined set of rules.

Wide area network:

If these devices on a network are scattered in different buildings,or different cities and these devices setup into several LAN's that are joined together into a larger structure called a Wide area network(WAN).

A Wan is composed of two or more Lan's. All these Lan's joined by a telephone line or dedicated cable. One or more machines act as the link between each Lan and Wan. These linking machines are called gateways. Depending on tasks perfomed by these linking machines,they are also called as Router and Bridge.

We all know Internet is not a single network. Internet is a collection of networks that communicate with each other through gateways.Gateways act as a relay between networks. It passes data from network to network searching for a destination address. Networks talk to each other through gateways. Gateways perform protocol translation from one network to another.

Bridge connects two or more networks that use the same protocol.

Router forwards datagrams around the network.

Note: Articles on Windows NT,Windows 2000 Server,Windows 2003 Server will come soon on my blog under the same NETWORKING section.

What is a Local Area Network?


Introduction:

A set of computers and peripherals connected together by a medium is called a network. All these devices on the netwok communicate with each other through a protocol. All these devices on a netwok can be in the same room or scattered through a building or scattered in different buildings or different cities. All these devices can be separated by many miles by the use of dedicated telephone lines or microwave etc.

Peripherals are nothing but Printers,Scanners,Modems,Plotters etc.
Protocol is a predefined set of rules.

Local Area Network:

If the devices on a network are located in a single place such as a building or a group of rooms,they are called a local area network. Usually all these devices on the network are connected by a single type of network cable in Lan's.

LAN Topologies:

The main dominant Lan topologies are Bus,Hub(Star) and ring.

Bus Topology:

Bus network consists of a single linear cable called a Bus(or Backbone). Each device is attached to this backbone through a junction box or transceiver. From each transceiver another short cable runs to the device's netwok adapter. Signal bounce is eliminated by a terminator at each end of the bus. Barrel connectors can be used to lengthen the cable. For regenerating signals Repeaters are used.Each device has a special address. Data is sent to all devices on the backbone. Each device examines every packet and accepts only messages addressed to them.

Main advantage of bus network is that it allows for a high speed bus. But performance degrades when more devices are added to the bus. Bus topology is good for small network. The entire network goes down if the backbone goes down.

Hub Topology:

This network uses a main cable called the backplane. From the backplane set of cables goes to hubs. All devices are connected to the ports of these hubs. We can set up small hub network with standard Ethernet cables. Also we can set up large hub network by using a high speed fibre optic backplane.The hub networks are easy to set up and maintain.

In this network all devices are connected by cable segments to a centralized hub. Signal travels through the hub to all the computers. The network functions normally if a computer goes down. This network requires more cable.

Ring Topology:

All the devices are connected on a single circle of cable. No termination required as in Bus topology. For regenerating signals no repeaters are used. The computers act as repeaters. The Ring networks are easy to set up and maintain.

Note: Articles on Windows NT,Windows 2000 Server,Windows 2003 Server will come soon on my blog under the same NETWORKING section.

How to make stock charts open in www.nseindia.com,www.bseindia.com and any other Web sites for Windows Xp users?


For any serious stock investor stock charts are very important. Before buying or selling stocks,stock investors analyze stock charts. After analyzing the charts they will take decision whether to buy,sell or not. So stock charts are one of the key points at the time of buying or selling stocks.

Unfortunately for Windows Xp users stock charts are not opening from nseindia.com,bseindia.com and some other sites. By default Win Xp is bundled with internet Explore 6.0. Unfortunately Sun Micro systems withdrawn support of J2SE Runtime Environment(JRE) to Win Xp. So java applications like stock charts are not opening for windows Xp users.

We have to download that software JRE 5.0 Update 9 for running stock charts. Go to http://java.sun.com site. On the main page you will find Downloads tab. Click downloads. Under Java technology click java SE. In this window you will find Java Run time environment(JRE) 5.0 Update 9. By the side of it you will find Download button. Just click it. In this window click the radio button “Accept license agreement”. Below this button you will find Windows Platform - J2SE Runtime Environment 5.0 Update 9. Below this you will find two files. You can download any one of the two files.

First file will download complete(JRE) 5.0 Update 9 software. After downloading this file you can install it.

Where as second file downloads only application file(245.76 kb). First download it. Then double click that file and install JRE from net. So while installing your computer must be connected to internet.

Thank You for visiting my Blog.

HAPPY INVESTMENT

Submit Site to Google,Yahoo,MSN Search and all other Search Engines. Submission is Free and Easy


Open www.google.com. At the top right hand corner of the page you will find Sign in link. Click that link. Then Google Accounts page will come. First create Google Account. So click create an account now link. Then it will ask your current email address and ask to choose some password for google account. After giving all details click create my account link.

Then Google will send verification link to your email address. First open your email box and click the verification link then only Google will activate your account. So your account is created.

open https://www.google.com/webmasters/sitemap. Then sign in to your account by giving email and password. Then in your account you will find add site box. Type your website in that box and click OK. It will ask site map also. If you have sitemap then give it. If you donot have sitemap then no problem. Forget about Sitemap. Google will take it's own time for indexing your webpages in Google. It depends on your website type,designing etc.

For one of my websites Google has taken just one day for indexing my pages. I have submitted my second site 5 days back. Still Google kept it in pending. So for this site it will take it's own time for indexing my pages.

Check your account regularly whether your site is accepted by Google or not. I will tell you simple check. Open www.google.com. In the search box type your website and click search. If Google shows your site in search results then your site is accepted by Google. If google does not show your site then your site is still not accepted by Google.

For submitting your site to Yahoo, open http://search.yahoo.com. You will find link at the bottom right corner of the page. Click submit your site link. In that page click submit your site for free link. Then it will ask Your yahoo ID and password. Type your yahoo ID and password and sign in. In that page it will ask submit url. Type your complete url and submit it. In the same page you can submit your site feed also. If you donot know your site feed no problem forget about it. Yahoo also take it's own time for indexing your pages.

For submitting your site to MSN Search open www.live.com site. In Live Search box Type your site and click search. In that page it will give message: we did not find your site. In the same page at bottom you will find link send the address to us. Click that link then type your url and submit it. Very simple. MSN also take it's own time for indexing your pages.

For submitting your site to 100+ search Engines, Open http://www.submitplus.com. In that page you will find links Free Top 10!, Free Best 100! First click Free Top 10! Link. Then type your URL and Email in the given boxes and click submit button. Then your site will be submitted to 10 search engines at free of cost.

Now click Best 100 link. Then in that page you will find select your engines. Click on that and choose pages 1-20. Then in another small window it shows 20 search engines with submit links. Submit your site to one by one by giving the details asked by that particular search engine. But in these lists some search engines are paid sites. So leave paid search engines and submit your site to free search engines. Try to submit your site to all given 100 search engines.If you want to submit your site to some more search engines then do like this. Open http://www.google.com. Then in the search box type search engines then click search. Google will show so many search engines. You just open every search engine site and check for submit your site link. Then submit your site to that particular search engine. This only requires a lot of patience. So you can submit your site to a lot of search engines freely. O.K !


Design Your Own Website using HTML


In this article I will tell you a simple webpage design using HTML and how to host it on www.freewebs.com. This article is for newbies only.

HTML documents use TAGS. A tag is a string in the language surrounded by a less than (<) and a greater (>) than sign. An opening tag is a string that does not begin with a slash (/). An ending tag is a string that begins with a slash (/). The region between an opening tag and a closing tag with the same string is referred to as an element.

An opening<html> and a closing </html> tag should surround the entire html document. We should also find opening and closing tags for <head> and <body> elements. An HTML document code should appear as shown below.

<HTML>
<HEAD>
.....
</HEAD>
<BODY>
.....
</BODY>
</HTML>

I will tell you some other simple tags.

The title of the HTML document is placed between the opening<TITLE> and closing </TITLE> tags. <TITLE> tags are placed within the <HEAD> tags.

<HR> tag places a horizontal Rule. This tag is within the <BODY> tags.

<BR> tag represents a line break

<P> tag represents a paragraph break.

<H1> ..... </H1> tags represents a level 1 heading.

<H2> ..... </H2> tags represents a level 2 heading.

<CENTER> ..... </CENTER> tags aligns the text between them centrally.

BGCOLOR this attribute is used in the opening <BODY> tag for setting the background color of Webpage.

If you want to give a link to yahoomail from your site, you can do that with the help of <A> tags like this.

<A HREF=http://www.yahoomail.com>yahoomail</A> Result : Thease tags underline yahoomail. So if you click yahoomail then it will take you to www.yahoomail.com

Now Design A simple Webpage:

Open Notepad. Type the following html code in Notepad and save it with a file name with an .html extension.(EX: save as index.html)

<html>
<head>
<title>Homepage of Praneel</title>
</head>
<body bgcolor=orange>
<h1><center>MY HOMEPAGE</center></h1>
<hr>
<h1>Praneel</h1>
D/No: 1-11 <br>
M.G. Road <br>
Vijayawada<br>
<hr>
<h1>About Me</h1>
I am studying 10th class in Adithya Public School,Vijayawada.
<p>
My present Aim is to get state rank.
<hr>
<h1>My links</h1>
<a href=http://www.yahoomail.com>yahoomail</a>
<hr>
</body>
</html>

Now save this as index.html then open the file in internet explorer. Now your Webpage will be like this.


Now I will tell you how to host this on www.freewebs.com site. Hosting is free.

Open www.freewebs.com. Then sign up for a free account. Choose a username and password and give email address and other details. Tick their terms and conditions. Click Next Step. Then click I AGREE.Then choose HTML mode then type your full name and choose site category then click nextstep. Now it will ask some details. It is optional so donot give any details. At top right corner you will find “Nothanks continue” link. Click that link. Then Welcome to freewebs link come.


Now click site manager. Here you will find upload a file. So you can upload your notepad file. Remember onething. You have to name your file as index.html in order to upload to freewebs site.


One thing is important. Freewebs site will send a verification link to your email address which you have given during filling the details for freewebs account. So open your email box and click the verification link sent by the freewebs site.

Now click upload a file. In the box give the path of your's index.html file by clicking the browse button. Now click upload file button. Then your index.html file will be uploaded to freewebs site. I have given user name as praneel. So my website name is like this.
http://www.freewebs.com/praneel Now you can check this site on net.

You can edit your index.html file at anytime and you can save it. For this open www.freewebs.com site. Then give your username and password and goto your account. There click Site manager button. Then you can observe your index.html file with EDIT,RENAME,DEL buttons. Click edit buttion then your html code will be open in another window. Do the necessary changes then go to file menu of WebEdit 1.9(Not internet explorer file menu) and click save. Then your index.html will be saved.

Without knowing HTML, You can also create your website at freewebs.com. For this do like this.

Open www.freewebs.com. Then sign up for a free account. Choose a username and password and give email address and other details. Tick their terms and conditions. Click Next Step. Then click I AGREE.Then Do not choose HTML mode. Here you have to choose one of the templates of Freewebs.com site. Rest of the procedure is almost same as above
.


How can you create HTML links?


1. Create a link to a site

Suppose we have text like below.

“If you want to download yahoo messenger please click here”.

Suppose you want to make the word “click” link to http://messenger.yahoo.com Then do like this.

Place <A> tag before CLICK and </A> tag after CLICK like this in the above sentence.

If you want to download yahoo messenger please <A>click</A> here.

Next in the <A> tag place the HREF attribute like this.

If you want to download yahoo messenger please
<A HREF=“http://messenger.yahoo.com” >click</A> here.

So we have create a link to yahoo messenger site.

2. Create a link to a page located in your computer.

If suppose you have “sai.html” document located in your computer.If you want to create a link to it then do like this

<A HREF=“sai.html” >sai</A>

3. Create a link to your e-mail address.

If suppose your e-mail address is sai122@yahoo.com then you will create a link to your e-mail address like this.
<A HREF=“mailto:sai122@yahoo.com” >e-mail me</A>


HTML Table Tags


1. <TABLE> ..... </TABLE>
These html tags specify data between them as a table. For kepting data in table you can use data cells.

2. <TABLE BORDER> ..... </TABLE>
Html does not display borders around the cells of the table. If you use BORDER attribute then html display borders using the lines.

3. <TABLE WIDTH=576> ..... </TABLE>
With the help of WIDTH attribute we can set the width of the table.

4. <TABLE ALIGN=CENTER> ..... </TABLE>
With these html tags table is created centrally on the screen.

5. <TABLE>
<CAPTION>caption of the table</CAPTION>
< ! - - table data - ->
</TABLE>
In between caption tags we can put a caption to the table.

6. <TABLE>
<CAPTION>caption of the table</CAPTION>
<TH>name 1<TH>name 2<TH>name 3
< ! - - table data - ->
</TABLE>
With <TH> tag we can put heading to cells. The text after <TH> tag is heading of a cell. In the above table there are three columns. So with the help of <TH> tags I put headings to three columns as above. Inside <TD> tag we can use ALIGN attributes left,center,right,justify for aligning the text.

7. <TR>
This tag creates new row of data.

8. <TABLE>
<CAPTION>caption of table</CAPTION>
<TH>name 1<TH>name 2<TH>name3
<TR><TD>some data<TD>some data<TD>some data
</TABLE>
There are three data cells in the above code. We can put data to the table after <TD> tag.

9. <TD></TD>
Since there is no data between <TD>tags this will become a blank data cell.

10. <TABLE>
<TR ALIGN=CENTER><TD>some data<TD>some data<TD>some data
</TABLE>
Since Align attribute center is in <TR> tag,the data in all data cells aligns centrally in data cells.

11. <TABLE>
<TR ALIGN=CENTER><TD>some data<TD ALIGN=LEFT>some data<TD>some data
</TABLE>
Here the data in second cell aligns left where as the data in first and third data cells aligns centrally in datacells.

12. <TABLE>
<TR VALIGN=TOP><TD>some data<TD>some data<TD>some data
</TABLE>
By VALIGN attribute we can do vertical alignment. In above table data is aligned to top of the data cells in the entire row.

13. <TABLE CELLSPACING=8> ..... </TABLE>
By using above attribute we can control the space between cells in a table.

14. <TABLE CELLPADDING=6> ..... </TABLE>
By using the above attribute we can set the distance from the cell edge to the cell data.


Tags For Formating The Body Text


1. <I> ..... </I>
These html tags italicize the text between them.

2. <B> ..... </B>
These html tags bold the text between them.

3. <FONT SIZE=7> ..... </FONT>
These html tags make the font size of the text between them to 7.
Size can be specified by any integer between 1 and 7.

4. <FONT COLOR=#FF0000> ..... </FONT>
These html tags make the font color of the text between them to red.

5. <FONT FACE= “ARIAL” > ..... </FONT>
These html tags make the font of the text between them to Arial.

6. <FONT SIZE=7 COLOR=#FF0000 FACE= “ARIAL” > ..... </FONT>
These html tags make the font size of the text between them to 7,font color of the text between them to red and font of the text between them to Arial.

7. <U> ..... </U>
These html tags underline the text between them.

8. <SUB> ..... </SUB>
These html tags place any text between them below the level of the line and in a smaller font.

9. <SUP> ..... </SUP>
These html tags place any text between them above the level of the line and in a smaller font.

10. <STRIKE> ..... </STRIKE>
These html tags place any text between them in strikethrough style.

11. <H1> ..... </H1>
These html tags identify text between them as a heading. This is level 1 heading. A total of six level headings are in HTML Language. Level 6 heading tags are <H6> ..... </H6> .The largest heading is <H1>. The smallest heading is <H6>. So Html enables users to identify headings and subheadings through these tags.

12. <H1 ALIGN=LEFT> ..... </H1>
These html tags align the level 1 heading to the left of the window.

13. <H2 ALIGN=CENTER> ..... </H2>
These html tags align the level 2 heading to the center of the window.

13. <H6 ALIGN=RIGHT> ..... </H6>
These html tags align the level 6 heading to the right of the window.