Wordpress Interview Questions and Answers

Wordpress Interview Questions and Answers:

1. What is WordPress?

WordPress is CMS(Content Management System) based on php and mysql.Its free and open source blogging tool.The world aproximately 22% websites used wordpress.Its now most popular blogging tool on internet network.

The main reason for its popularity is its admin very easy to use and manage.Its will work on apr. 60 million websites world wide.


2. Who and when developed wordpress?

The Matt Mullenweg and Mike Little is founder of wordpress.Its first release in 27 May 2003.The first version released is 0.7.

 

3. What is current version of wordpress?

The wordpress 3.5.1 version released on 24 January 2013.

 
4. What are the features of wordpress?

1. Simplicity,Make wordpress to manage easily that is its very easy to use.

2. Free open source ,its free to use wordpress.

3. Easy theme system,In wordpress we have thousand of good free theme to use.

4. Extends with plugins, we can extends the functionality of wordpress using thousands of free plugins or will create any plugin according to your requirements.

5. Community,WordPress has vibrant and supportive community.

6. Multilingual, wordpress is available on more than 70 languages.

7. Flexibility, with wordpress you will create any type of blog or website.

8. Comment, the built in comment system also make wordpress popular as you can comment your views on website.

9. Easy installation and upgrades.

10. Full standards compliance, Easy Importing,Cross-blog communication tools.


5. How many  tables wordpress have by default ?

By default wordpress have 11 tables.

1. wp_posts

2. wp_commentmeta

3. wp_comments

4. wp_links

5. wp_options

6. wp_postmeta

7. wp_terms

8. wp_term_relationships

9. wp_term_taxonomy

10.wp_usermeta

11.wp_users


6. What is the prefix of wordpress tables by default?

By default, wp_ is prefix of wordpress.


7. How you will pass a variable by value in WordPress.

Its same like we will work in c,

$a = &$b


8. How can we backup or import our WordPress content from admin panel?

For import content from wordpress admin panel goes to:-

WordPress admin -> Tools -> Import

This will create a xml file for our posts ,comments, category etc.


9. What are the functions commonly used in wordpress?

WordPress have lot of inbuilt functions.Some of commonly used function in wordpress are:-

1. wp_nav_menu() :- Displays a navigation menu created in wordpres admin menu.

2. is_page() :- Condition for check if page is displayed. Its return true or false.

3. get_excerpt() :- Displays the excerpt of the current post with read more link for display full post.

4. is_category() :- Condition for check if category is displayed. Its return true or false.

5. the_title():- Displays the title of the current post

6. the_content():- Displays the contents of the current post.


10. What is file structure in wordpress?

The main files used in wordpres are:-

1. index.php or home.php :- for home page or index page.

2. single.php :- for single post page.

3. page.php :- display the static pages.

4. category.php :- Display the category page.

5. archive.php :- For archive page display.

6. tag.php :- For display the tags page.

7. author.php :- For dispaly author page.

8. search.php :- For display the search result page.

9. 404.php :- For display 404 error page.

10. taxonomy.php :- For display the taxonomy archive.

11. attachment.php :- For managing the single attachments page.

12. date.php :- For managing date based archive.

13. header.php :- For managing top part of page.

14. footer.php :- For manage bottom part of pages.


11. What are the template tags in wordpress?

A template tag is code that instructs WordPress to “do” or “get” something.Like in header.php we will use the tag bloginfo(‘name’) to get information from user profile.

The the_title() template tag is used to display the post title.

wp_list_cats() are for display categories.

get_header() for getting header.

get_sidebar() for display the sidebar on page.

get_footer() for get the footer content on page.


12. What are the custom fields in wordpress?
 
We will add extra information to our post by using custom fields.Custom Fields are a form of meta-data that allows us to store arbitrary information with each WordPress post.

Meta-data is handled with key/value pairs. The key is the name of the meta-data element. The value is the information that will appear in the meta-data list on each individual post that the information is associated with.

To display the Custom Fields for each post, use the the_meta() template tag.

To fetch meta values use the get_post_meta() function.

For example we use custom fields:-

ID, ‘key’, true); ?>


13. Can wordPress use cookies?

Yes, wordpress use cookies.WordPress uses cookies, or tiny pieces of information stored on your computer, to verify who you are. There are cookies for logged in users.

 
14. If we are hacked in wordpress but steps have to do for prevent it?
 
The various steps have to do when you hacked:-

1. Change passwords for all users, especially Administrators and Editors.

2. Re-install the latest version of WordPress.

3. Make sure all of your plugins and themes are up-to-date.

4. Install security plugins like wp security for safe from hacked.

 
15. What is the wordpress loop?
 
The Loop are php code used by WordPress to display posts. Using The Loop, WordPress processes each post to be displayed on the current page.


16. What is the special meaning of _sleep and _wakeup?

_sleeps return the array of all variables than need to be saved, while _wakeup retrives them.


17. How to pass a variable by value in wordpress?

Put an ampersand like C++ in front of, like $a=&$b.

 
18. Are there are limitations to a wordpress website?

No, still not. We can use wordpress for e-commerce site, membership sites, photo galelries, and any other type of site we think of.

 
19. How to disable wordpress comment?

Look in to dashboard under Options – Discussion. There is a checkbox there for “allow people to post comments on the article” Try unchecking that.
Also – you can do it in the box on the right in the Write screen. That only affects the one post, though.

 
20. Why wordpress is better than blogger for blogging?


1. Customization and Flexibility

2. Hosting Opportunities

3. To customize the tiny image that people see in their address bar when they visit your blog, upload a blavatar.

4. The more tag allows you to display excerpts of your posts on your main posts page, instead of revealing the entire post.

5. To expand the text editor and hide the modules on the publishing screen, enable Distraction Free Writing.

6. Reproduce fully-functioning tweets — not just static screenshots of tweets — in posts, pages, and even comments with Twitter Embeds.

7. You can customize your post and page slugs, which can be handy when you want to create a URL that’s easier to remember (it’s also a good way to make posts search-friendly). Note that if you change a post slug, the old link will still work.

 8. Reproduce fully-functioning tweets — not just static screenshots of tweets — in posts, pages, and even comments with Twitter Embeds.

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XML Interview Questions and Answers

Latest XML Interview Questions and Answers:

What is XML?

• Extensible Markup Language (XML) is the universal language for data on the Web
• XML is a technology which allows us to create our own markup language.
• XML documents are universally accepted as a standard way of representing information in platform and language independent manner.
• XML is universal standard for information interchange.
• XML documents can be created in any language and can be used in any language.

What is the difference between XML and HTML?

XML is no way clashes with HTML, since they are for two different purposes.

HTML	XML
HTML is for displaying purpose.	whereas  XML is for data representation.
HTML is used to mark up text so it can be displayed to users.	XML is used to mark up data so it can be processed by computers.
HTML describes both structure and appearance	XML describes only content, or “meaning”
HTML uses a fixed, unchangeable set of tags	In XML, you make up your own tags

What are the benefits of XML?

There are many benefits of using XML on the Web :

• Simplicity- Information coded in XML is easy to read and understand, plus it can be processed easily by computers.
• Openness- XML is a W3C standard, endorsed by software industry market leaders.
• Extensibility - There is no fixed set of tags. New tags can be created as they are needed.
• Self-description- In traditional databases, data records require schemas set up by the database administrator. XML documents can be stored without such definitions, because they contain meta data in the form of tags and attributes.
• Contains machine-readable context information- Tags, attributes and element structure provide context information that can be used to interpret the meaning of content, opening up new possibilities for highly efficient search engines, intelligent data mining, agents, etc.

What is a well-formed XML document?

If a document is syntactically correct it can be called as well-formed XML documents. A well-formed document conforms to XML's basic rules of syntax:

Every open tag must be closed.
The open tag must exactly match the closing tag: XML is case-sensitive.
All elements must be embedded within a single root element.
Child tags must be closed before parent tags.
A well-formed document has correct XML tag syntax, but the elements might be invalid for the specified document type.

What is XML DOM Document?

XML Document object represents the whole XML document, and it is the root of a document tree. It gives access to entire XML document – Nodes and Elements, and it has its own properties.

What is XPath?

XPath is used to find information in an XML document and contains standard functions. XPath is the major element in XSLT, and it is w3c recommendation.

What is an attribute?

An attribute provides more or additional information about an element than otherwise.

Can we have empty XML tags?

Yes, we can have empty tags in XML. Empty tags are used to indicate elements that have no textual content.

What are the advantages of XML DOM Document?

Advantages of XML DOM:

• XML structure is traversable, and it can be randomly accessed by traversing the tree.
• XML structure is modifiable, and values can be added, changed and removed

What are the basic rules while writing XML?

These are the basic rules while writing XML:

• All XML should have a root element
• All tags should be closed
• XML tags are case sensitive
• All tags should be nested properly
• Tag names cannot contain spaces
• Attribute value should appear within quotes
• White space is preserved

What is XML Element?

An XML document contains XML Elements, and it starts from an element’s start tag to end tag. It can contain:

• Other elements within main element
• An Attribute
• text

What is a valid XML document?

If a document is structurally correct then it can be called as valid XML documents. A valid document conforms to the predefined rules of a specific type of document:

These rules can be written by the author of the XML document or by someone else.
The rules determine the type of data that each part of a document can contain.
Note:Valid XML document is implicitly well-formed, but well-formed may not be valid

What is CDATA?

CDATA is unparsed character data that cannot be parsed by the XML parser. Character < and > are illegal in XML elements. CDATA section starts with <![CDATA[“ and end with “]]>”.

How comment can be represented in XML?

Comment can be represented as <!- – comments – -> as like HTML. This comment symbol is applicable for single or multiple lines.

What are XML Namespaces?

XML namespaces are used to avoid element name conflicts, and it can be avoided by using prefix before the name.

Who is responsible for XML?

XML is a recommendation of the W3C – World Wide Web Consortium and the development are supervised by XML working group.

What is an XML Schema?

An XML schema gives the definition of an XML document, and it has following:

• Elements and attributes

• Elements that are child elements

• Order of child elements

• Data types of elements and attributes

What is well formed XML document?

A well-formed XML document must follow the following rules  –

• Every start tag should end with an end tag

• XML tags are case sensitive

• Empty tags are necessary to close with a forward slash

• All tags should be properly nested

Why XML has been used for development?

XML is used for development for following reasons:

• Used for Database driven websites
• Used to store data for e-commerce websites
• Used to transport and store data on internet
• XML is used for database and flat files
• Generate dynamic content by applying different style sheets

What is SGML?

SGML is large and powerful Standard Generalized markup Language which is used to define descriptions of the structure of different types of electronic document.

Can I execute a XML?

No, we cannot execute XML, and it is not a programming language to execute. It is just a markup language to represent the data.

What are the special characters used in XML?

<, > and & are the special characters used in XML. Because these characters are used for making tags.

What is a Processing Instruction in XML?

A Processing Intruction is the information which we would like to give to application. Through a Processing Instruction an application would get idea about how to process the document. A Processing Instruction can appear anywhere and any no. of times in a document.

How does the XML structure is defined?

XML document will have a structure which has to be defined before we can create the documents and work with them. The structural rules can be defined using many available technologies, but the following are popular way of doing so-

• Document Type Definition (DTD)
• Schema

What is DTD?

A Document Type Definition (DTD) defines the legal building blocks of an XML document. It defines rules for a specific type of document, including:

• Names of elements, and how and where they can be used
• The order of elements
• Proper nesting and containment of elements
• Element attributes

To apply a DTD to an XML document, you can:

Include the DTD's element definitions within the XML document itself.
Provide the DTD as a separate file, whose name you reference in the XML document.

What are differences between DTDs and Schema? 

Schema	DTD
Schema document is an XML document i.e., the structure of an XML document is specified by another XML document.	DTDs follow SGML syntax.
Schema supports variety of dataTypes similar to programming language.	In DTD everything is treated as text.
In Schema,  It is possible to inherit and create relationship among elements.	This is not possible in DTD without invalidating existing documents.
In Schema, It is possible to group elements and attributes so that they can be treated as single logical unit.	Grouping of elements and attributes is not possible in DTD.
In Schemas, it is possible to specify an upper limit for the number of occurrences of an element	It is not possible to specify an upper limit of an element in DTDs

What is a Complex Element?

A complex element is an XML element that contains other elements and/or attributes.

There are four kinds of complex elements:

1. empty elements
2. elements that contain only other elements
3. elements that contain only text
4. elements that contain both other elements and text

What is a Simple Element?

• A simple element is an XML element that can contain only text.
• A simple element cannot have attributes
• A simple element cannot contain other elements
• A simple element cannot be empty
• However, the text can be of many different types, and may have various restrictions applied to it.

What are namespaces? Why are they important?

A simple element is an XML element that can contain only text. Namespaces are a simple and straightforward way to distinguish names used in XML documents, no matter where they come from. XML namespaces are used for providing uniquely named elements and attributes in an XML instance They allow developers to qualify uniquely the element names and relationships and make these names recognizable, to avoid name collisions on elements that have the same name but are defined in different vocabularies.
They allow tags from multiple namespaces to be mixed, which is essential if data is coming from multiple sources.

What is XML parser?

An XML parser is a piece of software which can do following:

Check for well-formedness
Validate the document
Allows us to read, create or modify existing XML documents

What is SAX?

SAX-Simple API for XML processing. SAX provides a mechanism for reading data from an XML document. It is a popular alternative to the Document Object Model (DOM).SAX provides an event based processing approach unlike DOM which is tree based.

What are the interfaces of SAX?

The interfaces of SAX are:

• DocumentHandler- is used for getting event notification relating to a document.
• DTDHandler- is implemented to get the notifications related to declarations in DTD like entities and notations
• EntityResolver- is used for reading external entities.
• ErrorHandler- is used for handling error related notifications.

What is XSL?

eXtensible Stylesheet Language(XSL)  deals with most displaying the contents of XML documents.XSL consists of three parts:

• XSLT - a language for transforming XML documents
• XPath - a language for navigating in XML documents
• XSL-FO - a language for formatting XML documents

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Networking Interview Questions and Answers

Networking Interview Questions and Answers 2015:

What is a network?

It is a set of devices connected by communication links. A node can be a computer or any other device capable of sending and/or receiving data generated by other nodes on the network.
 
Define LAN, MAN and WAN?

LAN- A local area network (LAN) is a privately owned and links the devices in a single office, building or campus. It allows resources to be shared between personal computers and work stations. MAN- A metropolitan-area network (MAN) spreads over an entire city. It may be wholly owned and operated by a private company, eg local telephone company. WAN – A wide area network (WAN) provides long distance transmission of data, voice, image and video information over large geographic areas that comprise a country, a continent or even whole world.
 
What is TELNET ?

TELNET is a client –server application that allows a user to log on to a remote machine,giving the user access to the remote system. TELNET is an abbreviation of terminal Network.

What is switching?

Switching in data communication is of three types.

• Circuit switching
• Packet switching
• Message switching

What is a Link?

A link refers to the connectivity between two devices. It includes the type of cables and protocols used in order for one device to be able to communicate with the other.

What are the layers of the OSI reference model?

There are 7 OSI layers: Physical Layer, Data Link Layer, Network Layer, Transport Layer, Session Layer, Presentation Layer and Application Layer.
 
What is backbone network?

A backbone network is a centralized infrastructure that is designed to distribute different routes and data to various networks. It also handles management of bandwidth and various channels.
 
What is a LAN?

LAN is short for Local Area Network. It refers to the connection between computers and other network devices that are located within a small physical location.

What is a node?

A node refers to a point or joint where a connection takes place. It can be computer or device that is part of a network. Two or more nodes are needed in order to form a network connection.
 
What are routers?

Routers can connect two or more network segments. These are intelligent network devices that store information in its routing table such as paths, hops and bottlenecks. With this info, they are able to determine the best path for data transfer. Routers operate at the OSI Network Layer.
 
What is point to point link?

It refers to a direct connection between two computers on a network. A point to point connection does not need any other network devices other than connecting a cable to the NIC cards of both computers.

What is anonymous FTP?

Anonymous FTP is a way of granting user access to files in public servers. Users that are allowed access to data in these servers do not need to identify themselves, but instead log in as an anonymous guest.
 
What is subnet mask?

A subnet mask is combined with an IP address in order to identify two parts: the extended network address and the host address. Like an IP address, a subnet mask is made up of 32 bits.

Wat is the maximum length allowed for a UTP cable?

A single segment of UTP cable has an allowable length of 90 to 100 meters. This limitation can be overcome by using repeaters and switches.

What is data encapsulation?

Data encapsulation is the process of breaking down information into smaller manageable chunks before it is transmitted across the network. It is also in this process that the source and destination addresses are attached into the headers, along with parity checks.

Describe Network Topology

Network Topology refers to the layout of a computer network. It shows how devices and cables are physically laid out, as well as how they connect to one another.

What is VPN?

VPN means Virtual Private Network, a technology that allows a secure tunnel to be created across a network such as the Internet. For example, VPNs allow you to establish a secure dial-up connection to a remote server.

Briefly describe NAT.

NAT is Network Address Translation. This is a protocol that provides a way for multiple computers on a common network to share single connection to the Internet.

What is the job of the Network Layer under the OSI reference model?

The Network layer is responsible for data routing, packet switching and control of network congestion. Routers operate under this layer.

How does a network topology affect your decision in setting up a network?

Network topology dictates what media you must use to interconnect devices. It also serves as basis on what materials, connector and terminations that is applicable for the setup.

What is RIP?

RIP, short for Routing Information Protocol is used by routers to send data from one network to another. It efficiently manages routing data by broadcasting its routing table to all other routers within the network. It determines the network distance in units of hops.

What are different ways of securing a computer network?

There are several ways to do this. Install reliable and updated anti-virus program on all computers. Make sure firewalls are setup and configured properly. User authentication will also help a lot. All of these combined would make a highly secured network.

What is NIC?

NIC is short for Network Interface Card. This is a peripheral card that is attached to a PC in order to connect to a network. Every NIC has its own MAC address that identifies the PC on the network.
 
What is WAN?

WAN stands for Wide Area Network. It is an interconnection of computers and devices that are geographically dispersed. It connects networks that are located in different regions and countries.

What is the importance of the OSI Physical Layer?

The physical layer does the conversion from data bits to electrical signal, and vice versa. This is where network devices and cable types are considered and setup.

How many layers are there under TCP/IP?

There are four layers: the Network Layer, Internet Layer, Transport Layer and Application Layer.

What are proxy servers and how do they protect computer networks?

Proxy servers primarily prevent external users who identifying the IP addresses of an internal network. Without knowledge of the correct IP address, even the physical location of the network cannot be identified. Proxy servers can make a network virtually invisible to external users.

What is the function of the OSI Session Layer?

This layer provides the protocols and means for two devices on the network to communicate with each other by holding a session.  This includes setting up the session, managing information exchange during the session, and tear-down process upon termination of the session.

What is the importance of implementing a Fault Tolerance System? Are there limitations?
A fault tolerance system ensures continuous data availability. This is done by eliminating a single point of failure. However, this type of system would not be able to protect data in some cases, such as in accidental deletions.

What does 10Base-T mean?

The 10 refers to the data transfer rate, in this case is 10Mbps. The word Base refers to base band, as oppose to broad band. T means twisted pair, which is the cable used for that network.

What is a private IP address?

Private IP addresses are assigned for use on intranets. These addresses are used for internal networks and are not routable on external public networks. These ensures that no conflicts are present among internal networks while at the same time the same range of private IP addresses are reusable for multiple intranets since they do not “see” each other.

What is NOS?

NOS, or Network Operating System, is specialized software whose main task is to provide network connectivity to a computer in order for it to be able to communicate with other computers and connected devices.

What is DoS?

DoS, or Denial-of-Service attack, is an attempt to prevent users from being able to access the internet or any other network services. Such attacks may come in different forms and are done by a group of perpetuators. One common method of doing this is to overload the system server so it cannot anymore process legitimate traffic and will be forced to reset.
 
What is OSI and what role does it play in computer networks?

OSI (Open Systems Interconnect) serves as a reference model for data communication. It is made up of 7 layers, with each layer defining a particular aspect on how network devices connect and communicate with one another. One layer may deal with the physical media used, while another layer dictates how data is actually transmitted across the network.

What is the purpose of cables being shielded and having twisted pairs?

The main purpose of this is to prevent crosstalk. Crosstalks are electromagnetic interferences or noise that can affect data being transmitted across cables.

What is the advantage of address sharing?

By using address translation instead of routing, address sharing provides an inherent security benefit. That’s because host PCs on the Internet can only see the public IP address of the external interface on the computer that provides address translation and not the private IP addresses on the internal network.

What are MAC addresses?

MAC, or Media Access Control, uniquely identifies a device on the network. It is also known as physical address or Ethernet address. A MAC address is made up of 6-byte parts.

What is the equivalent layer or layers of the TCP/IP Application layer in terms of OSI reference model?
The TCP/IP Application layer actually has three counterparts on the OSI model: the Session layer, Presentation Layer and Application Layer.

How can you identify the IP class of a given IP address?

By looking at the first octet of any given IP address, you can identify whether it’s Class A, B or C. If the first octet begins with a 0 bit, that address is Class A. If it begins with bits 10 then that address is a Class B address. If it begins with 110, then it’s a Class C network.

What is the main purpose of OSPF?

OSPF, or Open Shortest Path First, is a link-state routing protocol that uses routing tables to determine the best possible path for data exchange.

What are firewalls?

Firewalls serve to protect an internal network from external attacks. These external threats can be hackers who want to steal data or computer viruses that can wipe out data in an instant. It also prevents other users from external networks from gaining access to the private network.

Describe star topology

Star topology consists of a central hub that connects to nodes. This is one of the easiest to setup and maintain.

What are gateways?

Gateways provide connectivity between two or more network segments. It is usually a computer that runs the gateway software and provides translation services. This translation is a key in allowing different systems to communicate on the network.

What is the disadvantage of a star topology?

One major disadvantage of star topology is that once the central hub or switch get damaged, the entire network becomes unusable.

What is SLIP?

SLIP, or Serial Line Interface Protocol, is actually an old protocol developed during the early UNIX days. This is one of the protocols that are used for remote access.

Give some examples of private network addresses.

10.0.0.0 with a subnet mask of 255.0.0.0
 172.16.0.0 with subnet mask of 255.240.0.0
 192.168.0.0 with subnet mask of 255.255.0.0

What is tracert?

Tracert is a Windows utility program that can used to trace the route taken by data from the router to the destination network. It also shows the number of hops taken during the entire transmission route.

What are the functions of a network administrator?

A network administrator has many responsibilities that can be summarize into 3 key functions: installation of a network, configuration of network settings, and maintenance/troubleshooting of networks.

Describe at one disadvantage of a peer to peer network.

When you are accessing the resources that are shared by one of the workstations on the network, that workstation takes a performance hit.

What is Hybrid Network?

A hybrid network is a network setup that makes use of both client-server and peer-to-peer architecture.

What is DHCP?

DHCP is short for Dynamic Host Configuration Protocol. Its main task is to automatically assign an IP address to devices across the network. It first checks for the next available address not yet taken by any device, then assigns this to a network device.

What is the main job of the ARP?

The main task of ARP or Address Resolution Protocol is to map a known IP address to a MAC layer address.

What is TCP/IP?

TCP/IP is short for Transmission Control Protocol / Internet Protocol. This is a set of protocol layers that is designed to make data exchange possible on different types of computer networks, also known as heterogeneous network.
 
How can you manage a network using a router?

Routers have built in console that lets you configure different settings, like security and data logging. You can assign restrictions to computers, such as what resources it is allowed access, or what particular time of the day they can browse the internet. You can even put restrictions on what websites are not viewable across the entire network.

What protocol can be applied when you want to transfer files between different platforms, such between UNIX systems and Windows servers?
Use FTP (File Transfer Protocol) for file transfers between such different servers. This is possible because FTP is platform independent.

What is the use of a default gateway?

Default gateways provide means for the local networks to connect to the external network. The default gateway for connecting to the external network is usually the address of the external router port.

One way of securing a network is through the use of passwords. What can be considered as good passwords?
Good passwords are made up of not just letters, but by combining letters and numbers. A password that combines uppercase and lowercase letters is favorable than one that uses all upper case or all lower case letters. Passwords must be not words that can easily be guessed by hackers, such as dates, names, favorites, etc. Longer passwords are also better than short ones.

What is the proper termination rate for UTP cables?

The proper termination for unshielded twisted pair network cable is 100 ohms.

What is netstat?

Netstat is a command line utility program. It provides useful information about the current TCP/IP settings of a connection.

What is the number of network IDs in a Class C network?

For a Class C network, the number of usable Network ID bits is 21. The number of possible network IDs is 2 raised to 21 or 2,097,152. The number of host IDs per network ID is 2 raised to 8 minus 2, or 254.

What happens when you use cables longer than the prescribed length?

Cables that are too long would result in signal loss. This means that data transmission and reception would be affected, because the signal degrades over length.
 
What common software problems can lead to network defects?

Software related problems can be any or a combination of the following:
 – client server problems
 – application conflicts
 – error in configuration
 – protocol mismatch
 – security issues
 – user policy and rights issues

What is ICMP?

ICMP is Internet Control Message Protocol. It provides messaging and communication for protocols within the TCP/IP stack. This is also the protocol that manages error messages that are used by network tools such as PING.
 
What is Ping?

Ping is a utility program that allows you to check connectivity between network devices on the network. You can ping a device by using its IP address or device name, such as a computer name.

What is peer to peer?

Peer to peer are networks that does not reply on a server. All PCs on this network act as individual workstations.

What is DNS?

DNS is Domain Name System. The main function of this network service is to provide host names to TCP/IP address resolution.

What advantages does fiber optics have over other media?

One major advantage of fiber optics is that is it less susceptible to electrical interference. It also supports higher bandwidth, meaning more data can be transmitted and received. Signal degrading is also very minimal over long distances.
 
What is the difference between a hub and a switch?

A hub acts as a multiport repeater. However, as more and more devices connect to it, it would not be able to efficiently manage the volume of traffic that passes through it. A switch provides a better alternative that can improve the performance especially when high traffic volume is expected across all ports.

What are the different network protocols that are supported by Windows RRAS services?

There are three main network protocols supported: NetBEUI, TCP/IP, and IPX.

What are the maximum networks and hosts in a class A, B and C network?

For Class A, there are 126 possible networks and 16,777,214 hosts
 For Class B, there are 16,384 possible networks and 65,534 hosts
 For Class C, there are 2,097,152 possible networks and 254 hosts

What is the standard color sequence of a straight-through cable?

orange/white, orange, green/white, blue, blue/white, green, brown/white, brown.

What protocols fall under the Application layer of the TCP/IP stack?

The following are the protocols under TCP/IP Application layer: FTP, TFTP, Telnet and SMTP.

You need to connect two computers for file sharing. Is it possible to do this without using a hub or router?
Yes, you can connect two computers together using only one cable. A crossover type cable can be use in this scenario. In this setup, the data transmit pin of one cable is connected to the data receive pin of the other cable, and vice versa.

What is ipconfig?

Ipconfig is a utility program that is commonly used to identify the addresses information of a computer on a network. It can show the physical address as well as the IP address.
 
What is the difference between a straight-through and crossover cable?

A straight-through cable is used to connect computers to a switch, hub or router. A crossover cable is used to connect two similar devices together, such as a PC to PC or Hub to hub.
 
What is client/server?

Client/server is a type of network wherein one or more computers act as servers. Servers provide a centralized repository of resources such as printers and files. Clients refers to workstation that access the server.

When you move the NIC cards from one PC to another PC, does the MAC address gets transferred as well?

Yes, that’s because MAC addresses are hard-wired into the NIC circuitry, not the PC. This also means that a PC can have a different MAC address when the NIC card was replace by another one.

Explain clustering support

Clustering support refers to the ability of a network operating system to connect multiple servers in a fault-tolerant group. The main purpose of this is the in the event that one server fails, all processing will continue on with the next server in the cluster.

In a network that contains two servers and twenty workstations, where is the best place to install an Anti-virus program?
An anti-virus program must be installed on all servers and workstations to ensure protection. That’s because individual users can access any workstation and introduce a computer virus when plugging in their removable hard drives or flash drives.

Describe Ethernet.

Ethernet is one of the popular networking technologies used these days. It was developed during the early 1970s and is based on specifications as stated in the IEEE. Ethernet is used in local area networks.

What are some drawbacks of implementing a ring topology?

In case one workstation on the network suffers a malfunction, it can bring down the entire network. Another drawback is that when there are adjustments and reconfigurations needed to be performed on a particular part of the network, the entire network has to be temporarily brought down as well.

What is the difference between CSMA/CD and CSMA/CA?

CSMA/CD, or Collision Detect, retransmits data frames whenever a collision occurred. CSMA/CA, or Collision Avoidance, will first broadcast intent to send prior to data transmission.

What is SMTP?

SMTP is short for Simple Mail Transfer Protocol. This protocol deals with all Internal mail, and provides the necessary mail delivery services on the TCP/IP protocol stack.

What is multicast routing?

Multicast routing is a targeted form of broadcasting that sends message to a selected group of user, instead of sending it to all users on a subnet.

What is the importance of Encryption on a network?

Encryption is the process of translating information into a code that is unreadable by the user. It is then translated back or decrypted back to its normal readable format using a secret key or password. Encryption help ensure that information that is intercepted halfway would remain unreadable because the user has to have the correct password or key for it.

How are IP addresses arranged and displayed?

IP addresses are displayed as a series of four decimal numbers that are separated by period or dots. Another term for this arrangement is the dotted decimal format. An example is 192.168.101.2

Explain the importance of authentication.

Authentication is the process of verifying a user’s credentials before he can log into the network. It is normally performed using a username and password. This provides a secure means of limiting the access from unwanted intruders on the network.

What do mean by tunnel mode?

This is a mode of data exchange wherein two communicating computers do not use IPSec themselves. Instead, the gateway that is connecting their LANs to the transit network creates a virtual tunnel that uses the IPSec protocol to secure all communication that passes through it.

What are the different technologies involved in establishing WAN links?

Analog connections – using conventional telephone lines; Digital connections – using digital-grade telephone lines; switched connections – using multiple sets of links between sender and receiver to move data.

What is one advantage of mesh topology?

In the event that one link fails, there will always be another available. Mesh topology is actually one of the most fault-tolerant network topology.

When troubleshooting computer network problems, what common hardware-related problems can occur?
A large percentage of a network is made up of hardware. Problems in these areas can range from malfunctioning hard drives, broken NICs and even hardware startups. Incorrectly hardware configuration is also one of those culprits to look into.

What can be done to fix signal attenuation problems?

A common way of dealing with such a problem is to use repeaters and hub, because it will help regenerate the signal and therefore prevent signal loss. Checking if cables are properly terminated is also a must.

How does dynamic host configuration protocol aid in network administration?

Instead of having to visit each client computer to configure a static IP address, the network administrator can apply dynamic host configuration protocol to create a pool of IP addresses known as scopes that can be dynamically assigned to clients.

Explain profile in terms of networking concept?

Profiles are the configuration settings made for each user. A profile may be created that puts a user in a group, for example.

What is sneakernet?

Sneakernet is believed to be the earliest form of networking wherein data is physically transported using removable media, such as disk, tapes.

What is the role of IEEE in computer networking?

IEEE, or the Institute of Electrical and Electronics Engineers, is an organization composed of engineers that issues and manages standards for electrical and electronic devices. This includes networking devices, network interfaces, cablings and connectors.

What protocols fall under the TCP/IP Internet Layer?

There are 4 protocols that are being managed by this layer. These are ICMP, IGMP, IP and ARP.

When it comes to networking, what are rights?

Rights refer to the authorized permission to perform specific actions on the network. Each user on the network can be assigned individual rights, depending on what must be allowed for that user.

What is one basic requirement for establishing VLANs?

A VLAN requires dedicated equipment on each end of the connection that allows messages entering the Internet to be encrypted, as well as for authenticating users.

What is IPv6?

IPv6 , or Internet Protocol version 6, was developed to replace IPv4. At present, IPv4 is being used to control internet traffic, butis expected to get saturated in the near future. IPv6 was designed to overcome this limitation.

What is RSA algorithm?

RSA is short for Rivest-Shamir-Adleman algorithm. It is the most commonly used public key encryption algorithm in use today.
 
What is mesh topology?

Mesh topology is a setup wherein each device is connected directly to every other device on the network. Consequently, it requires that each device have at least two network connections.

What is simplex?

It is the mode of communication between two devices in which flow of data is unidirectional. i.e. one can transmit and other can receive. E.g. keyboard and monitor.

What is half-duplex?

It is the mode of communication between two devices in which flow of data is bi-directional but not at the same time. ie each station can transmit and receive but not at the same time. E.g walkie-talkies are half-duplex system.

What is full duplex?

It is the mode of communication between two devices in which flow of data is bi-directional and it occurs simultaneously. Here signals going in either direction share the capacity of the link. E.g. telephone

What are the advantages of broadcast network.?

• a single communication channel is shared by all computers.
• packets are transmitted and received by all the computer.
• address field is attached to whom it is intended.
• multi-casting is used in network.

What do you mean by point to point network?

Point to point network consist of many connections between individual pair of machines.large networks are point to point.Routing algorithm plays an important in point to point network.It uses stored ad forword technique.It is a packet switching network.

What are the design issue of layers ?

The design issue of layer are

• Addressing technique.ie source and destination address
• Types of communication
• Error control
• Order of message.
• Speed matching
• Multiplexing and demultiplexing.

Define pulse amplitude modulation?

It is an analog to digital conversion method which takes analog signals, samples it and generates a series of pulse based on the results of the sampling. It is not used in data communication because the series of pulses generated still of any amplitude. To modify it we use pulse code modulation.

Define pulse code modulation?

Pulse code Modulation modifies pulses created by PAM to create a completely digital signal. For this PCM first quantizes the PAM pulse. Quantization is the method of assigning integral values in a specific tange to sampled instances.PCM is made up of four separate processes: PAM, quantization, binary encoding and line encoding.

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HTML Interview Questions and Answers

Best HTML Interview Questions and Answers:

What is HTML?

HTML is short for HyperText Markup Language, and is the language of the World Wide Web. It is the standard text formatting language used for creating and displaying pages on the Web. HTML documents are made up of two things: the content and the tags that formats it for proper display on pages.

What are tags?

Content is placed in between HTML tags 0in order to properly format it. It makes use of the less than symbol (<) and the greater than symbol (>).

Do all HTML tags come in pair?

No, there are single HTML tags that does not need a closing tag. Examples are the img tag and br tags.

What are some of the common lists that can be used when designing a page?

You can insert any or a combination of the following list types:

• ordered list
• unordered list
• definition list
• menu list
• directory list

What is contained in HTML markup?

It consists of :

• Character-based data types
• Several key components, including elements (and their attributes)
• Character references and entity references.
• Also the document type declaration.

What is body in HTML document?

The body element defines the documents' body. It contains all the contents of the document (like text, images, colors, graphics, etc.).

What is the difference between HTML elements and tags? 
HTML elements communicate to the browser how to render text. When surrounded by angular brackets <> they form HTML tags. For the most part, tags come in pairs and surround text.

What is head in HTML document?

The head of an HTML document is an unordered collection of information about the document. The HEAD contains general information, or meta-information, about the document. The head appears first in a document above the BODY.

What does DOCTYPE mean?

 The term DOCTYPE tells the browser which type of HTML is used on a webpage. In turn, the browsers use DOCTYPE to determine how to render a page. Failing to use DOCTYPE or using a wrong DOCTYPE may load your page in Quirks Mode. 

What’s the difference between standards mode and quirks mode?

 Quirks Mode is a default compatibility mode and may be different from browser to browser, which may result to a lack of consistency in appearance from browser to browser.

Do all character entities display properly on all systems?

No, there are some character entities that cannot be displayed when the operating system that the browser is running on does not support the characters. When that happens, these characters are displayed as boxes.

What is image map?

Image map lets you link to many different web pages using a single image. You can define shapes in images that you want to make part of an image mapping.

What is the advantage of collapsing white space?

White spaces are blank sequence of space characters, which is actually treated as a single space character in html. Because the browser collapses multiple space into a single space, you can indent lines of text without worrying about multiple spaces. This enables you to organize the html code into a much more readable format.

Can attribute values be set to anything or are there specific values that they accept?

Some attribute values can be set to only predefined values. Other attributes can accept any numerical value that represents the number of pixels for a size.

How do you insert a copyright symbol on a browser page?

To insert the copyright symbol, you need to type © or & #169; in an HTML file.


Is there any way to keep list elements straight in an html file?

By using indents, you can keep the list elements straight. If you indent each subnested list in further than the parent list that contains it, you can at a glance determine the various lists and the elements that it contains.

If you see a web address on a magazine, to which web page does it point?

Every web page on the web can have a separate web address. Most of these addresses are relative to the top-most web page. The published web address that appears within magazines typically points this top-most page. From this top level page, you can access all other pages within the web site.

What is the use of using alternative text in image mapping?

When you use image maps, it can easily become confusing and difficult to determine which hotspots corresponds with which links. Using alternative text lets you put a descriptive text on each hotspot link.

Do older html files work on newer browsers?

Yes, older html files are compliant to the HTML standard. Most older files work on the newer browsers, though some features may not work.

Does a hyperlink apply to text only?

No, hyperlinks can be used on text as well as images. That means you can convert an image into a link that will allow user to link to another page when clicked.

If the user’s operating system does not support the needed character, how can the symbol be represented?

In cases wherein their operating system does not support a particular character, it is still possible to display that character by showing it as an image instead.

How do you change the number type in the middle of a list?

The "li" tag includes two attributes – type and value. The type attribute can be used to change the numbering type for any list item. The value attribute can change the number index.

What are style sheets?

Style sheets enable you to build consistent, transportable, and well-defined style templates. These templates can be linked to several different web pages, making it easy to maintain and change the look and feel of all the web pages within a site.

What bullet types are available?

With ordered lists, you can select to use a number of different list types including alphabetical and Roman numerals. The type attribute for unordered lists can be set to disc, square, or circle.

How do you create multicolored text in a webpage?

To create text with different colors, use the font tags for every character that you want to apply a color. You can use this tag combination as many times as needed, surrounding a single character or an entire word.

Why are there both numerical and named character entity values?

The numerical values are taken from the ASCII values for the various characters, but these can be difficult to remember. Because of this, named character entity values were created to make it easier for web page designers to use.

What is the advantage of grouping several check boxes together?

Although checkboxes don’t affect one another, grouping checkboxes together helps to organize them. Checkbox buttons can have their own name and do not need to belong to a group. A single web page can have many different groups of checkboxes.

What will happen if you overlap sets of tags?

If two sets of html tags are overlapped, only the first tag will be recognized. You will recognize this problem when the text does not display properly on the browser screen.

What are the limitations when serving XHTML pages?

Perhaps the biggest issue is the poor browser support XHTML currently enjoys. Internet Explorer and a number of other user agents cannot parse XHTML as XML. Thus, it is not the extensible language it was promised to be. There are many other issues. Take your pick.

What is the syntax difference between a bulleted list and numbered list?

Bulleted lists use the "ul" tag, which stands for “unordered,” whereas "ol" is used to create an ordered list.

What is the difference between "div" and "frame" tags?

A div tag is a generic container element for grouping and styling, whereas a frame tag creates divisions within a web page and should be used within the frameset tag. The use of frame and frameset are no longer popular and are now being replaced with the more flexible iframe, which has become popular for embedding foreign elements (ie. Youtube videos) into a page.

What are the reasons for validating a HTML?

To ensure one shared HTML coding standard in the World Wide WebTo ensure smooth spiderability of the HTML pageTo ensure better positioning of the HTML in Search Engines

What is span in HTML?

The SPAN is used for highlighting text of any color desired, for adding colored text, for adding background image to text. SPAN doesn't cause a line break. It delimits text and it allows styles to be applied to a 'elemental' region, or for the 'elemental' region to be identified, without causing a break in the text flow.

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XML Interview Questions and Answers

Latest XML Interview Questions and Answers:

What is XML?

Extensible Markup Language (XML) is the universal language for data on the Web
XML is a technology which allows us to create our own markup language.
XML documents are universally accepted as a standard way of representing information in platform and language independent manner.
XML is universal standard for information interchange.
XML documents can be created in any language and can be used in any language.

What is the difference between XML and HTML?

XML is no way clashes with HTML, since they are for two different purposes.

HTML	XML
HTML is for displaying purpose.	whereas  XML is for data representation.
HTML is used to mark up text so it can be displayed to users.	XML is used to mark up data so it can be processed by computers.
HTML describes both structure and appearance	XML describes only content, or “meaning”
HTML uses a fixed, unchangeable set of tags	In XML, you make up your own tags

What are the benefits of XML?

There are many benefits of using XML on the Web :

Simplicity- Information coded in XML is easy to read and understand, plus it can be processed easily by computers.

Openness- XML is a W3C standard, endorsed by software industry market leaders.

Extensibility - There is no fixed set of tags. New tags can be created as they are needed.

Self-description- In traditional databases, data records require schemas set up by the database administrator. XML documents can be stored without such definitions, because they contain meta data in the form of tags and attributes.

Contains machine-readable context information- Tags, attributes and element structure provide context information that can be used to interpret the meaning of content, opening up new possibilities for highly efficient search engines, intelligent data mining, agents, etc.

Separates content  from presentation- XML tags describe meaning not presentation. The motto of HTML is: "I know how it looks", whereas the motto of XML is: "I know what it means, and you tell me how it should look." The look and feel of an XML document can be controlled by XSL style sheets, allowing the look of a document to be changed without touching the content of the document. Multiple views or presentations of the same content are easily rendered.

Supports multilingual documents and Unicode-This is important for the internationalization of applications.

Facilitates the comparison and aggregation of data - The tree structure of XML documents allows documents to be compared and aggregated efficiently element by element.

Can embed multiple data types - XML documents can contain any possible data type - from multimedia data (image, sound, video) to active components (Java applets, ActiveX).

Can embed existing data - Mapping existing data structures like file systems or relational databases to XML is simple. XML supports multiple data formats and can cover all existing data structures and .

Provides a 'one-server view' for distributed data - XML documents can consist of nested elements that are distributed over multiple remote servers. XML is currently the most sophisticated format for distributed data - the World Wide Web can be seen as one huge XML database.



What is a well-formed XML document?

If a document is syntactically correct it can be called as well-formed XML documents. A well-formed document conforms to XML's basic rules of syntax:

Every open tag must be closed.
The open tag must exactly match the closing tag: XML is case-sensitive.
All elements must be embedded within a single root element.
Child tags must be closed before parent tags.
A well-formed document has correct XML tag syntax, but the elements might be invalid for the specified document type.

What is XML DOM Document?

XML Document object represents the whole XML document, and it is the root of a document tree. It gives access to entire XML document – Nodes and Elements, and it has its own properties.

What is XPath?

XPath is used to find information in an XML document and contains standard functions. XPath is the major element in XSLT, and it is w3c recommendation.

What is an attribute?

An attribute provides more or additional information about an element than otherwise.

Can we have empty XML tags?

Yes, we can have empty tags in XML. Empty tags are used to indicate elements that have no textual content.


What are the advantages of XML DOM Document?

Advantages of XML DOM:

• XML structure is traversable, and it can be randomly accessed by traversing the tree.

• XML structure is modifiable, and values can be added, changed and removed

What are the basic rules while writing XML?

These are the basic rules while writing XML:

• All XML should have a root element
• All tags should be closed
• XML tags are case sensitive
• All tags should be nested properly
• Tag names cannot contain spaces
• Attribute value should appear within quotes
• White space is preserved

What is XML Element?

An XML document contains XML Elements, and it starts from an element’s start tag to end tag. It can contain:

• Other elements within main element
• An Attribute
• text

What is a valid XML document?

If a document is structurally correct then it can be called as valid XML documents. A valid document conforms to the predefined rules of a specific type of document:

These rules can be written by the author of the XML document or by someone else.
The rules determine the type of data that each part of a document can contain.
Note:Valid XML document is implicitly well-formed, but well-formed may not be valid


What is CDATA?

CDATA is unparsed character data that cannot be parsed by the XML parser. Character < and > are illegal in XML elements. CDATA section starts with <![CDATA[“ and end with “]]>”.

How comment can be represented in XML?

Comment can be represented as <!- – comments – -> as like HTML. This comment symbol is applicable for single or multiple lines.

What are XML Namespaces?

XML namespaces are used to avoid element name conflicts, and it can be avoided by using prefix before the name.

Who is responsible for XML?

XML is a recommendation of the W3C – World Wide Web Consortium and the development are supervised by XML working group.

What is an XML Schema?

An XML schema gives the definition of an XML document, and it has following:

• Elements and attributes

• Elements that are child elements

• Order of child elements

• Data types of elements and attributes

What is well formed XML document?

A well-formed XML document must follow the following rules  –

• Every start tag should end with an end tag

• XML tags are case sensitive

• Empty tags are necessary to close with a forward slash

• All tags should be properly nested

Why XML has been used for development?

XML is used for development for following reasons:

• Used for Database driven websites
• Used to store data for e-commerce websites
• Used to transport and store data on internet
• XML is used for database and flat files
• Generate dynamic content by applying different style sheets

What is SGML?

SGML is large and powerful Standard Generalized markup Language which is used to define descriptions of the structure of different types of electronic document.

Can I execute a XML?

No, we cannot execute XML, and it is not a programming language to execute. It is just a markup language to represent the data.

What are the special characters used in XML?

<, > and & are the special characters used in XML. Because these characters are used for making tags.


What is a Processing Instruction in XML?

A Processing Intruction is the information which we would like to give to application. Through a Processing Instruction an application would get idea about how to process the document. A Processing Instruction can appear anywhere and any no. of times in a document.


How does the XML structure is defined?

XML document will have a structure which has to be defined before we can create the documents and work with them. The structural rules can be defined using many available technologies, but the following are popular way of doing so-

• Document Type Definition (DTD)
• Schema

What is DTD?

A Document Type Definition (DTD) defines the legal building blocks of an XML document. It defines rules for a specific type of document, including:

Names of elements, and how and where they can be used
The order of elements
Proper nesting and containment of elements
Element attributes
To apply a DTD to an XML document, you can:

Include the DTD's element definitions within the XML document itself.
Provide the DTD as a separate file, whose name you reference in the XML document.

What are differences between DTDs and Schema?

Schema	DTD
Schema document is an XML document i.e., the structure of an XML document is specified by another XML document.	DTDs follow SGML syntax.
Schema supports variety of dataTypes similar to programming language.	In DTD everything is treated as text.
In Schema,  It is possible to inherit and create relationship among elements.	This is not possible in DTD without invalidating existing documents.
In Schema, It is possible to group elements and attributes so that they can be treated as single logical unit.	Grouping of elements and attributes is not possible in DTD.
In Schemas, it is possible to specify an upper limit for the number of occurrences of an element	It is not possible to specify an upper limit of an element in DTDs

What is a Complex Element?

A complex element is an XML element that contains other elements and/or attributes.

There are four kinds of complex elements:

1. empty elements
2. elements that contain only other elements
3. elements that contain only text
4. elements that contain both other elements and text

What is a Simple Element?

• A simple element is an XML element that can contain only text.
• A simple element cannot have attributes
• A simple element cannot contain other elements
• A simple element cannot be empty
• However, the text can be of many different types, and may have various restrictions applied to it.

What are namespaces? Why are they important?

A simple element is an XML element that can contain only text. Namespaces are a simple and straightforward way to distinguish names used in XML documents, no matter where they come from. XML namespaces are used for providing uniquely named elements and attributes in an XML instance They allow developers to qualify uniquely the element names and relationships and make these names recognizable, to avoid name collisions on elements that have the same name but are defined in different vocabularies.
They allow tags from multiple namespaces to be mixed, which is essential if data is coming from multiple sources.

What is XML parser?

An XML parser is a piece of software which can do following:

Check for well-formedness
Validate the document
Allows us to read, create or modify existing XML documents

What is SAX?

SAX-Simple API for XML processing. SAX provides a mechanism for reading data from an XML document. It is a popular alternative to the Document Object Model (DOM).SAX provides an event based processing approach unlike DOM which is tree based.

What are the interfaces of SAX?

The interfaces of SAX are:

DocumentHandler- is used for getting event notification relating to a document.
DTDHandler- is implemented to get the notifications related to declarations in DTD like entities and notations
EntityResolver- is used for reading external entities.
ErrorHandler- is used for handling error related notifications.


What is XSL?

eXtensible Stylesheet Language(XSL)  deals with most displaying the contents of XML documents.XSL consists of three parts:

XSLT - a language for transforming XML documents
XPath - a language for navigating in XML documents
XSL-FO - a language for formatting XML documents

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