Networking Hub

What is a Hub?

A hub functions as the central connection point of a network. It joins together the workstations, printers, and servers on a network, so they can communicate with each other. Each hub has a number of ports that connect it to the other devices via a network cable.



How does a Hub work?

• A hub is an inexpensive way to connect devices on a network. A data travel around a network in ‘packets’ and a hub forward these data packets out to all the devices connected to its ports.

• As a hub distributes packets to every device on the network, when a packet is destined for only one device, every other device connected to the hub receives that packet.
• Because all the devices connected to the hub are contending for transmission of data the individual members of a shared network will only get a percentage of the available network bandwidth. This process can slow down a busy network.

Hubs classify as Layer 1 devices in the OSI model. At the physical layer, hubs can support little in the way of sophisticated networking. Hubs do not read any of the data passing through them and are not aware of their source or destination. Essentially, a hub simply receives incoming packets, possibly amplifies the electrical signal, and broadcasts these packets out to all devices on the network - including the one that originally sent the packet! 

Technically speaking, three different types of hubs exist:

• passive
• active
• intelligent

Passive hubs do not amplify the electrical signal of incoming packets before broadcasting them out to the network.

Active hubs, on the other hand, do perform this amplification, as does a different type of dedicated network device called a repeater. Some people use the terms concentrator when referring to a passive hub and multiport repeater when referring to an active hub.


Intelligent hubs add extra features to an active hub that are of particular importance to businesses. An intelligent hub typically is stackable (built in such a way that multiple units can be placed one on top of the other to conserve space). It also typically includes remote management capabilities via SNMP and virtual LAN (VLAN) support.

Read More

Asp.Net Basic Controls - Check Boxes

Check Box Control :

A check box displays a single option that the user can either check or unchecked. Check box provide more then one option and user can select more then one option at a time.

ASP Code :
          <asp:CheckBox ID="CheckBox1" runat="server" Text="Maruti" />

Property :

Property	Description
Text	The text displayed next to the check box
Checked	Specifies whether it is selected or not, default is false
ForeColor	Set font color of text in checkbox
TextAlign	Set position of text left or right

Event :

Events	Description
CheckedChanged	Event occurs when selection change in checkbox

Other Control :
 

Label	TextBox	Button	HyperLink
CheckBox	CheckBoxList	RadioButton	RadioButtonList
Image	ImageButton	ImageMap	Calender
DropDownList	ListBox	FileUpload

Read More

Asp.Net Basic Controls - Button

Button Control:

ASP .Net provides three types of button controls: buttons, link buttons and image buttons. As the names suggest a button displays text within a rectangular area, a link button displays text that looks like a hyperlink. And an Image Button displays an image.

 ASP Code:
                   <asp:Button ID="Button1" runat="server" Text="Button" />

Property:

Property	Description
Text	The text displayed by the button. This is for button and link button controls only.
Height	Set height of button in px
Width	Set width of button in px
PostBackUrl	Set Page name on which go after button click
OnClientClick	Set your own function which active on button click

Events:

Events	Description
Click	Button_click event generate on code page. This part use for coding
Command	Button_Command event generate on code page. This part use for Database command

Other Control :

Label	TextBox	Button	HyperLink
CheckBox	CheckBoxList	RadioButton	RadioButtonList
Image	ImageButton	ImageMap	Calender
DropDownList	ListBox	FileUpload

Read More

Asp.Net Basic Controls - TextBox

TextBox Control:

• Text box controls are typically used to accept input from the user. A text box control can accept one or more lines to text depending upon the setting of the TextMode attribute.

 

Asp Code:

        <asp:TextBox ID="txtstate" runat="server" ></asp:TextBox>

Property:

Property	Description
Height	Set height of label in px
Width	Set width of label in px
TextMode	SingleLine : MultiLine : Password :
ForeColor	Set font color as your need
Font	Set font style and attribute
BackColor	Set label back ground color

Other Control :

Label	TextBox	Button	HyperLink
CheckBox	CheckBoxList	RadioButton	RadioButtonList
Image	ImageButton	ImageMap	Calender
DropDownList	ListBox	FileUpload

Read More

Asp.Net Basic Controls - Label

Label Control:

• Label controls provide an easy way to display text which can be changed from one execution of a page to the next. If you want to display a text that does not change, you use the literal text.

Asp code:

               <asp:Label ID="Label1" runat="server" Text="Your Name :"></asp:Label>

Property:

Property	Description
Text	Set Label text to display
Height	Set height of label in px
Width	Set width of label in px
ForeColor	Set font color as your need
Font	Set font style and attribute
BackColor	Set label back ground color

Other Control :

Label	TextBox	Button	HyperLink
CheckBox	CheckBoxList	RadioButton	RadioButtonList
Image	ImageButton	ImageMap	Calender
DropDownList	ListBox	FileUpload

Read More

Difference between GET and POST

Ch- 6 DWD

Difference between GET and POST

Sr. No	GET	POST
1	GET request is sent via the URL string (appended to the URI with a question-mark as separator), which is visible.	POST request is encapsulated in the body of the HTTP request and can't be seen.
2	GET request goes via URL, so it has a limitation for its length. It can't be more than 255 characters long.	POST request becomes a part of the body of the HTTP request and there is no size limitation.
3	GET request is comparatively faster as it's relatively simpler to create a GET request.	The time spent in the encapsulation of the POST request in the HTTP body is saved in this case.
4	Only ASCII characters allowed. GET request is sent via URL string and as we all know that URL can be text-only, so GET can carry only text data.	No restrictions. Binary data is also allowed. POST has no such restriction and it can carry both text as well as binary data.
5	GET is less secure compared to POST because data sent is part of the URL. Never use GET when sending passwords or other sensitive information!	POST is a little safer than GET because the parameters are not stored in browser history or in web server logs
6	Data is visible to everyone in the URL.	Data is not displayed in the URL.

Read More