Top 50 Desktop Support Interview Questions Answers Study Material Notes Tutorial

Top 50 Desktop Support Interview Questions Answers Study Material Notes Tutorial

Top 50 Desktop Support Interview Questions Answers Study Material Notes Tutorial:-In  this  cyberpoint9 tutorial we are going to describe about the  Desktop Support Engineer and Server Engineer Interview Questions Answers  which is asked  in ethical hacking  cyber programming or in Desktop Support Engineer. And also we will describe that how can we crack interview of various examination  in ethical hacking and computer Science. When ever we want to learn any thing the things become more earlier is somebody/tutorial/study material taught us through Examples. Here we have tried to describe each and every concept of  Desktop Support Engineer and Server Engineer course with examples in the light of cyberpoint9.com  best  Short tutorial using simple and best possible example. These examples are so simple that even a beginner who had never even heard about hacking and Cyber law or Desktop Support Engineer can easily learn and understand How  the  Desktop Support Engineer works in our today’s Technical Field. This is  the best  tutorial/Study Material  very beneficial for beginners  as well as Professional.

Desktop  &Networking  Question & Answers

 1.What is IP address?

IP address is an identifier for a Computer or Device.

Class A IP Address 1 – 126, Class B IP Address 128 – 191, Class C IP Address 192 –223. And 127.0.0.1 is Loop back IP address. It will check the System Connectivity. Each machine connected to the Internet has an address known as an Internet Protocol address (IP address). The IP address takes the form of four numbers separated by dots, for example: 192.168.0.1 

You want to see System IP address goes to

Start- Run- Type cmd – type ipconfig /all

 You want to confirm any system connected in the system network type ping 192.168.0.1 (192.168.0.1 this system IP address)

 2.What is subnet mask?

Subnet mask is used for identify the Network.

Example:

For a class A address, a standard subnet mask is 255.0.0.0,

For a class B address, a standard subnet mask is 255.255.0.0,

For a class C address, a standard subnet mask is 255.255.255.0,

 3.What is DNS?

Domain Naming Service. It‘ll Resolve IP Address to Hostname (FQDN) and Hostname to IP address. In DNS there are two Zones.

  1. Forward Lookup Zone
  2. Reverse Lookup Zone.

FQDN – Fully Qualified Domain Name

 4.What is WINS?

Windows Internet Naming Service. It is used to resolve NetBIOS name to IP address & Vice versa. Short for Windows Internet Naming Service, a system that determines the IP address associated with a particular network computer. This is called name resolution. WINS supports network client and server computers running Windows and can provide name resolution for other computers with special arrangements. Determining the IP address for a computer is a complex process when DHCP servers assign IP addresses dynamically. For example, it is possible for DHCP to assign a different IP address to a client each time the machine logs on to the network.

WINS uses a distributed database that is automatically updated with the names of computers currently available and the IP address assigned to each one.

DNS is an alternative system for name resolution suitable for network computers with fixed IP addresses.

  1. What is DHCP?

Dynamic Host Configuration Protocol. It is used to Assign IP address automatically to the Client Machine.

DHCP is a protocol used by networked computers (clients) to obtain IP addresses and other parameters such as the default gateway, subnet mask, and IP addresses of DNS servers from a DHCP server. It facilitates access to a network because these settings would otherwise have to be made manually for the client to participate in the network.

DHCP operations fall into four basic phases. These phases are IP lease request, IP lease offer, IP lease selection, and IP lease acknowledgement

DHCP discovery

DHCP offers

DHCP requests

DHCP acknowledgement

What protocol and port does DHCP use?

DHCP, like BOOTP runs over UDP, utilizing ports 67 and 68.

DNS Root Hints in Windows 2003

Root Hints are a vital cog in configuring your DNS Server.  If your server receives a query for an unknown domain, then the root hints give a clue as to where to search for the answer.  Maybe you were lucky and the root hints magically configured themselves correctly.  Perhaps it was a triumph for planning that you examined the root hints as soon as you ran DCPROMO.  However, in my opinion you cannot be a successful DNS troubleshooter without understanding root hints.

DHCP in Windows Server 2003

D ynamic        – Means that clients IP address may change

H ost             – Indicates that this is a system for clients, e.g. XP machines

C onfiguration  – A clue that you are in charge of the options, e.g. DNS Server

P rotocol         – The rules controlling the flow of packets between client and server

DHCP Address Leases

Lease is a good name for a DHCP IP property.  Take for example the 8 day default lease;  if the client is shutdown for 2 days, when it restarts it will continue to have the same IP address.  Halfway through their lease clients attempt to renew their lease.  IPCONFIG /all will show you the lease, while /renew will do what it says, top up the lease.

Only reduce the duration if you are short of IP addresses.  For example, if you only have 250 IP addresses but 300 possible clients.  It also makes sense to set short leases if you are likely to discontinue a scope in the near future.

Here is a table summarising how a DHCP service results in clients getting an IP address.  If you are interested in seeing these packets, use Network monitor to capture DHCP in action.  Here are the classic 4 packets that clients exchange during a lease negotiation.

Client  Server
DHCPDiscover  –> <— DHCPOffer
DHCPRequest   –> <— DHCPack
   
 DHCPInform  Server check that it is Authorized in Active Directory

 

Note 1: DHCPRequest may seem strange, but it comes into play if there are two DHCP servers and both make an offer to a potential client.

Note 2: DHCPack.  Once in a blue moon you see DHCPNack this is a negative acknowledgement which mean, ‘ I do no know you’.  The most likely cause of Nack is the client is trying to renew an IP address from the wrong DHCP server.

Scope Options.

Take the time to investigate Scope Options, this the most likely place that I will win my bet that you will find a new setting which will improve your network performance.  These options can be set at the Scope Level, Server Level, Reservation Level or at the Class Level (Tricky).  So find all four places and make up your mind which would be the best level for your network.

Examples of DHCP Scope Options:

  • Router (Default Gateway), DNS Servers (006)
  • Domain Name (015) WINS (044 and 046)

 Classes (Advanced Tab)

  • Vendor Class – Windows 98 Machines
  • User Class – Routing and Remote Access
  • Creating your own User Class

Address Reservation

Reserving IP addresses is useful in two situations, for file and print servers and for important machines where leases are in short supply.  How does DHCP know which machine to lease a particular IP?  The answer is by its MAC address (also called NIC or Physical address).  In Windows 2003 when you enter the MAC address DHCP strips out the hyphens if you absentmindedly include them amongst the HEX numbers.  To find the MAC address ping the machine then type arp -a.

Remember that you can set DHCP Options for the reservations; after all that may have been the very reason why you decided to make reservations in the first place.

Authorize – DHCP Server

In a Windows Server 2003 (or 2000) domain all DHCP servers need to be authorized in Active Directory.  This is an example of Microsoft’s new security initiative, and an attempt to eliminate rogue DHCP servers set up junior administrators in a large company.  So, you need to logon (or RunAs) a member of the Enterprise Admins group.  Then right click the DHCP server icon, and authorize.

Incidentally, The RIS service also needs to be authorized before it becomes active.

Activate – DHCP Scope

Even after you authorize a server, each scope must be activated individually.  So, right click the scope to activate (or deactivate).  Keep your eye on the red or green arrows to judge your success.  Note you may have to refresh from the server icon, often pressing F5 is not enough.

 

  1. What is Relay Agent?

If we want to assign IP address automatically to other subnets then we need to require relay agent. DHCP server always uses broadcast traffic to assign IP address for the clients. But Router does not forward broadcast Packets. Router only broadcast unicast packets. To overcome this problem across subnets we are using DHCP Relay agent.

 

  1. What is Clustering?

Clustering means it is a group of two or more server running same application and fault tolerance it is called Clustering.

Windows 2000 Advanced server support and Data center server support 8 Nodes.

Windows 2003 enterprise edition and Datacenter server support 4 Nodes.

But, Windows 2000 server and 2003 Standard Edition Not support for Clustering.

 

  1. What is Transferring and Seizing?

Transferring: If your Domain Computer wants to Shutdown for a while, you can transfer roles to another domain controller.

Seizing:  If your Computer wants to Shutdown Permanently then you can seize your Roles from your Computer to another Computer by using Ntdsutil.

 

  1. What is Device manager?

The Device Manager is a tool included with Microsoft Windows operating systems that allows the user to display and control the hardware attached to the computer. When a piece of hardware is not working, the offending hardware is highlighted where the user can deal with it.

 

  1. Definition of CMOS? (Complementary Metal oxide Semiconductor)

A part of the motherboard that maintains system variables in static RAM. It also supplies a real-time clock that keeps track of the date, day and time. CMOS Setup is typically accessible by entering a specific sequence of keystrokes during the POST at system start-up.

 

  1. FSMO (Flexible Single Master Operation) Roles?
  1. Schema Master: It will Contain all the object Attributes, Nothing but user Properties.
  2. Domain naming Master: If we are adding any server or Removing any server from the Domain. This will contain all the information.
  3. PDC Emulator: Any password changes by other Domain it will be updated to PDC Emulator, It will work in mixed mode, where NT B dc domain is there.
  4. RID Master: It will give SID ( Security Identify) to any objects created in that Domain.
  5. Infrastructure Master: It will have the group information for that Domain.

 

  1. Volume types?

1) Simple volume,

2) Stripped volume

3) Spanned Volume

4) Mirrored Volume (Raid 1)

5) Raid 5 Volume.

 

Raid 1 (Mirrored Volume)

Mirrored volumes are created using two physical disks. A mirrored volume required same amount of unallocated space on each physical disk is used. When the data is written to a mirrored volume the data is written to a disk and then synchronized on the second disk an exact copy of the data is available on both physical disks.

Raid 5

Raid 5 volume provides fault tolerance and performance. But write operation is slower than stripped volume. Here we need 3 hard disk. Here it is a distributed data, data and parity. If data loss we can get information from parity

 

13. FAT file system want to convert in to NTFS file system which command?

 

Convert E: /FS: NTFS

 

14. What is NAT?                                      

 

Network Address Translator. Network devices that are assigned private IP address cannot access Internet site directly therefore traffic must be routed through a net device called NAT.

Here we have to assign Private IP address and a Public IP address

 

15. What is ADS?

 

Ads is the Active directory service It will store all the information database  in the centralized location and allow the users to access the resources from the network.

In windows Ntds.dit database

IN Win NT SAM database

Active Directory is an implementation of LDAP directory services by Microsoft for use in Windows environments. Active Directory allows administrators to assign enterprise-wide policies, deploy programs to many computers, and apply critical updates to an entire organization. An Active Directory stores information and settings relating to an organization in a central, organized, accessible database. Active Directory networks can vary from a small installation with a few hundred objects, to a large installation with millions of objects.

Active Directory is a directory service used to store information about the network resources across a domain.

An Active Directory (AD) structure is a hierarchical framework of objects. The objects fall into three broad categories — resources (e.g. printers), services (e.g. e-mail), and users (accounts, or users and groups). The AD provides information on the objects, organizes the objects, controls access, and sets security.

Each object represents a single entity — whether a user, a computer, a printer, an application, or a shared data source—and its attributes. Objects can also be containers of other objects. An object is uniquely identified by its name and has a set of attributes—the characteristics and information that the object can contain—defined by a schema, which also determines the kind of objects that can be stored in the AD.

Each attribute object can be used in several different schema class objects. These schema objects exist to allow the schema to be extended or modified when necessary. However, because each schema object is integral to the definition of AD objects, deactivating or changing these objects can have serious consequences because it will fundamentally change the structure of AD itself. A schema object, when altered, will automatically propagate through Active Directory and once it is created it can only be deactivated — not deleted. Changing the schema usually requires a fair amount of planning

Active directory Logical Unit => Schema, Domain Tree

Active Directory Physical Unit  => OU, Site, Objects

 

Schema

Flexible single master operation:

 

Forest-wide FSMO Roles:

  • Schema Master that manages modifications to the AD schema and its replication to other Domain controllers.
  • Domain Naming Master that manages adding, and some modification operations for domains.

 

Domain-wide FSMO Roles:

  • Relative ID Master that allocates security RIDs to DCs to assign to new AD security principals (users, groups or computer objects). It also manages objects moving between domains.
  • Infrastructure Master that maintains security identifiers, GUIDs, and DNs for objects referenced across domains. Most commonly it updates user and group links.
  • PDC Emulator that emulates a Windows NT Primary Domain Controller (PDC). It is also the favored DC for other DCs in replicating and confirming password information, and is the authoritative source of time in the domain.

 

Lightweight Directory Access Protocol (LDAP)

In computer networking, the Lightweight Directory Access Protocol, or LDAP (It is a networking protocol for querying and modifying directory services running over TCP/IP.

 

A directory is a set of information with similar attributes organized in a logical and hierarchical manner. The most common example is the telephone directory, which consists of a series of names (either of a person or organization) organized alphabetically, with an address and phone number attached.

 

A client starts an LDAP session by connecting to an LDAP server, by default on TCP port 389. The client then sends operation requests to the server, and the server sends responses in turn. With some exceptions the client need not wait for a response before sending the next request, and the server may send the responses in any order.

 

The basic operations are:

  • Start TLS – optionally protect the connection with Transport Layer Security (TLS), to have a more secure connection
  • Bind – authenticate and specify LDAP protocol version
  • Search – search for and/or retrieve directory entries
  • Compare – test if a named entry contains a given attribute value
  • Add a new entry
  • Delete an entry
  • Modify an entry
  • Modify DN – move or rename an entry
  • Abandon – abort a previous request
  • Extended Operation – generic operation used to define other operations
  • Unbind – close the connection (not the inverse of Bind)

FSMO PARTITION

Application partition

Schema Partition

Configuration Partition

 

  1. What is global catalog?

 

When you installing a new domain in the forest it is called as global catalog. It will have all the information object of entire forest

 

  1. What’s the difference between Windows 2000 and Windows XP?

Windows 2000 and Windows XP are essentially the same operating system (known internally as Windows NT 5.0 and Windows NT 5.1, respectively.) Here are some considerations if you’re trying to decide which version to use:

Windows 2000 benefits

  • Windows 2000 has lower system requirements, and has a simpler interface (no “Styles” to mess with).
  • Windows 2000 is slightly less expensive, and has no product activation.
  • Windows 2000 has been out for a while, and most of the common problems and security holes have been uncovered and fixed.
  • Third-party software and hardware products that aren’t yet XP-compatible may be compatible with Windows 2000; check the manufacturers of your devices and applications for XP support before you upgrade.

Windows XP benefits

  • Windows XP is somewhat faster than Windows 2000, assuming you have a fast processor and tons of memory (although it will run fine with a 300 Mhz Pentium II and 128MB of RAM).
  • The new Windows XP interface is more cheerful and colorful than earlier versions, although the less-cartoon “Classic” interface can still be used if desired.
  • Windows XP has more bells and whistles, such as the Windows Movie Maker, built-in CD writer support, the Internet Connection Firewall, and Remote Desktop Connection.
  • Windows XP has better support for games and comes with more games than Windows 2000.
  • Windows XP is the latest OS – if you don’t upgrade now, you’ll probably end up migrating to XP eventually anyway, and we mere mortals can only take so many OS upgrades.
  • Manufacturers of existing hardware and software products are more likely to add Windows XP compatibility now than Windows 2000 compatibility.
  1. Difference bet domain and workgroup.

Domains
Domains are collections of computers grouped for management purposes; they share a group name. Domains let users’ access resources using a single logon. Administrators don’t have to create multiple user accounts for a single user to give that user access to all domain resources.

From a security perspective, a domain is a set or collection of computers that share a common security database and a common security policy. NT domains advance the concepts seen in LAN Manager for UNIX and LAN Server domains. Each domain has a unique domain name.

Workgroups
The terms workgroup and domain are used extensively in Microsoft networking and refer to the management mechanisms available to network members. Workgroups imply decentralized management, whereas domains imply centralized control.

Workgroups are collections of computers grouped just for viewing purposes; each computer user is responsible for managing its security functions. A workgroup can consist of NT Workstations, NT Servers, UNIX computers running Server Message Block (SMB) services, and others. They communicate using a common set of networking protocols at all seven layers of the OSI model

  1. Difference between NT4.0 & windows 2000

 

  • File system difference (NTFS, FAT, FAT32)
  • In winnt server concept pdc and bdc but there is no concept in 2000.
  • In winnt server sam database r/w format in pdc and read only format in bdc ,but in 2000 domain and every domain controller sam database read/writer format .
    2000 server can any time any moment become server or member of server simple add/remove dcpromo. But in winnt you have to reinstall operating system.
  • Even though Windows 2000 is built on the Windows NT architecture, Microsoft has added many new features (Plug and Play, USB support, Recovery Console, IntelliMirror, Group Policy, Active Directory, integration of IIS and Terminal Services) 

 

  1. What is Boot.ini?

The “boot.ini” is a Microsoft initialization file found on the Microsoft Windows NT Microsoft Windows 2000, and Microsoft Windows XP operating systems. This file is always located on the root directory of the primary hard disk drive. In other words, it is located at “C:\” directory or the “C Drive”. This file is used by Microsoft Windows as a method of displaying a menu of operating systems currently on the computer and allowing the user to easily select which operating system to load. In addition, this file is also used to point to the locations of each of the operating systems. 

Basic example of the boot.ini file:

[boot loader]
timeout=5
default=multi(0)disk(0)rdisk(1)partition(1)\WINDOWS
[operating systems]
multi(0)disk(0)rdisk(1)partition(1)\WINDOWS=”Microsoft Windows XP Home Edition” /fastdetect

In the above example, the boot.ini contains two sections, the “[boot loader]”, and “[operating systems]”. Within the boot loader section there are two lines. The “timeout” line is used for how long the boot menu time should be displayed, in seconds; we recommend that the timeout be set to at least five if you wish the computer to boot faster and commonly use the default operating systems. The “default” line is the default operating system that the boot.ini will load. If multiple operating systems are in the boot.ini, the default operating system will be automatically selected and used if the user does not specify a different operating system by the time the timeout value expires.

The next section, or the “operating system” section, is used to list and specify the location of each of the operating systems installed on the computer. Below is a listing of each of the options.

 

 

Option Description
multi(x) This option is used with IDE and ESDI drives and is also used with SCSI drives for computers using Windows NT. The number used in the above example is “0”, this number is the adapter’s number and should always be “0” for computers that rely on the BIOS to load system files.

  • In a computer using only IDE this option will work with up to four hard disk drives.
  • In a computer using only SCSI this option will work with the first two drives on the primary SCSI controller.
  • Finally, if a computer is using IDE and SCSI this option will work with the IDE drives on the first controller.
scsi(x) If the computer has a SCSI controller and is not using BIOS to load the system files, the boot.ini may have “scsi(x)” instead of “multi(x).
disk(x) The disk on the controller. If “multi(x)” is used used, this value will always be “0”. However, if “scsi(x)” is defined, this value will be SCSI address.
rdisk(x) Which disk on the controller is being used. In the above example we are using an rdisk of “1”, which indicates the second disk on the primary controller is being used. This value may be between “0” and “3” and is always set to “0” when “scsi(x)” is being used.
paritions(x) Which partition the operating system is on. In the above example, the operating system is on the first partition of the drive. 
\WINDOWS=”…” Finally, the last portion of this line defines the directory of where windows is located and what the boot menu should display as the operating system. In the above example, the boot menu would display “Microsoft Windows XP Home Edition” as a selection.

Example of the boot menu:

If multiple operating systems are setup in the boot.ini, as the computer is booting you will see a menu similar to the below example. This allows the user to select between multiple operating systems. If your computer does not have multiple operating systems, but this menu still appears each time your computer boots, it is likely that your boot.ini is improperly configured.

 

 

 

 

 

Please select the operating system to start:

Microsoft Windows XP Home Edition
Microsoft Windows 2000

Use the up and down arrow keys to move the highlight to your choice.
Press ENTER to choose.

 

 

For troubleshooting and advanced startup options for Windows, press F8. 

 

How to modify the boot.ini:

The boot.ini file is a hidden system file located in the root directory of your primary hard disk drive. To edit this file we recommend you follow the below steps.

  1. From Windows, open an MS-DOS prompt by clicking “Start” and then “Run” and typing “cmd” in the text box. If you are not able to get into a MS-DOS prompt to edit the boot.ini file, boot into the recovery console to edit the file. Additional information about the recovery console can be found on document CH000627.
  2. At the MS-DOS prompt, type:

    C:\ <press enter>
    C:\ cd\ <press enter>
    C:\ attrib -r -a -s -h boot.ini <press enter>
    C:\ edit boot.ini <press enter>

  1. What is SMTP, pop3? Port number for the same

 Short for Simple Mail Transfer Protocol, a protocol for sending e-mail messages between servers. Most e-mail systems that send mail over the Internet use SMTP to send messages from one server to another; the messages can then be retrieved with an e-mail client using either POP or IMAP. In addition, SMTP is generally used to send messages from a mail client to a mail server. This is why you need to specify both the POP or IMAP server and the SMTP server when you configure your e-mail application.

Port number: 25

POP3 (Post Office Protocol 3) is the most recent version of a standard protocol for receiving e-mail. POP3 is a client/server protocol in which e-mail is received and held for you by your Internet server. Periodically, you (or your client e-mail receiver) check your mail-box on the server and download any mail, probably using POP3.

Port number : 110

 

  1. About types of Printer?

  

Any of the current types of printers satisfies the work and cost requirements for someone. Each has strengths and weaknesses. Choose your type of printer based on which of the features previously discussed are important to your work, then choose the specific printer that best suits both your tasks and pocketbook.

Impact Printers

With this type of printer something strikes paper & ribbon together to form a character, like a typewriter.

 

Advantages: Less expensive
Fast (some types)
Can make multiple copies with multipart paper
Disadvantages:   Noisy!
Print quality lower in some types.
Poor graphics or none at all.

Types of Impact Printers

1.       Dot matrix

2.       Daisy Wheel

3.       Chain and Band printer

Dot Matrix   Forms characters using row(s) of pins, 9, 18, or 24 which impact the ribbon on top of the paper. Also called pin printers.

The more pins, the smoother-looking the characters.

Most dot matrix printers have the characteristics below:

 

 

Bi-directional – prints left to right and also right to left
Tractor feed – uses sprockets to pull continuous-feed paper
Friction feed – uses pressure to pull single sheets
Advantages: Inexpensive
Can do multi-copy forms
Disadvantages: Can be slow
Loud
Graphics of low quality, if possible at all
Daisy Wheel   Characters are fully formed on the “petals”, like typewriter keys.
 
Advantages:  Best print quality
Disadvantages:  Very slow – 20 to 80 cps

Only one font can be used at a time because you must change out the Daisy Wheel to change fonts.

Cannot print graphics.

 

Chain and Band Printers   Uses characters on a band or chain that is moved into place before striking the characters onto the paper.

Advantages:  Very fast
   up to 3000 lpm (lines per minute)
Disadvantages:  Very expensive
Very loud

 

Non-Impact Printers

 
This type of printer does not involve actually striking the paper. Instead, it uses ink spray or toner powder.  

 

Advantages: Quiet!
Can handle graphics and often a wider variety of fonts than impact printers.
Disadvantages:   More expensive
Slower

Types of Non-Impact Printers

Ink Jet     Sprays ink onto paper to form characters

Advantages:  Quiet
High quality text and graphics. Some can do color.
Disadvantages:  Cannot use multiple-copy paper
Ink can smear
Thermal    Uses heat on chemically treated paper to form characters. Fax machines that use rolls of paper are also of this type.

Advantages:  Quiet
Disadvantages:  Relatively slow
Expensive, requiring special paper
Cannot use multiple-copy paper
 
Page Printer    Works like a copy machine, using toner and a heat bar. Laser printers are in this category.

Advantages:  Quiet
Faster than other non-impact printers, from 4 to 16 ppm (pages per minute)
High quality print and graphics. Some can do color.
Disadvantages:  More expensive than impact printers
Cannot use multiple-copy paper
 

Thus, Things to Consider When Choosing a Printer:

How much output? What speed is needed?
Is heavy-duty equipment necessary?
Quality of output needed?  Letter quality?
Near letter quality?
Draft?
Location of printer? How big a footprint can be handled?
Is loudness important?
Multiple copies needed?  
Color print needed  

 

  1. Explain about Printer Spooler?

 

Spooler Introduction

The Printer Spooler enables the printer to be shared among multiple processes. This allows each process to see a virtual printer which it can print to and also allows a process to submit a file for printing. It can be used by both native tasks and by virtual tasks via the `vprinter’ module.

Spooler Operation

When a file is submitted for printing, its name is added to a list. A separate process processes this list in order to print the files. The list is processed in a FIFO (First In First Out) fashion. Although scheduling algorithms are available including SJF (Shortest Job First) and LJF (Longest Job First), a FIFO system was used in order to maintain simplicity and functionality. A virtual printer can also be opened allowing a process to print to a file when it doesn’t know how much is to be printed. When the file is closed, it is added to the list. This is used by the `vprinter’ module for emulating printer ports.

When the thread handling the printing of files is initially created, it looks in the spool directory and if there are any files there it automatically adds them to the list. The spool directory is defined in the header file `<vmm/spooler.h>’ and is by default set to spool.

Because of the dual access to the spool list by both the thread adding a spool file and the thread processing the spool list, access to the list is protected by a semaphore.

If the Print Spooler service fails when printing, when Windows starts or it can not be restarted, the usual reason is that one or more printer drivers is defective.  If the Print Spooler service is not running, the Printers and Faxes folder will be empty and you can not use it to remove (or add) printers or printer drivers

 

  1. How to edit registry manually to clean up spooler and drivers?

 

Here’s how to clean up the print spooler stuff if any third party kit is not available or you prefer to do things manually.

 

Warning! be very careful using regedit – if you delete the wrong things, you may render your computer inoperative!

  1. open regedit (e.g. click Start, key regedit and press Enter)
  2. navigate to

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Print\Environments\Windows NT x86\Drivers under this key, there will be the keys Version-2 and Version-3 (one or the other of these may be absent – not a problem) the sub-keys under these contain the printer driver configuration information delete all the sub-keys inside Version-2 and Version-3, but not these keys themselves.

The Microsoft Knowledgebase article at http://support.microsoft.com/default.aspx?scid=kb;en-us;312052  lists some other registry entries to delete, but this is not usually necessary.

  1. Open a Command Prompt window
  2. Key the commands
    net stop spooler
    net start spooler
  3. Open Windows Explorer
  4. Navigate to %systemroot%\system32\spool\printers\ and delete any files there.  By default, this is where the print spooler stores print files.
  5. Navigate to %systemroot%\system32\spool\drivers\w32x86 (%systemroot% is usually Windows, but it might be winnt or something else; this is set when the OS is installed).
  6. Inside w32x86, there will be folders with the names 2 and 3 (one or more of these may be absent – not a problem) delete all of the files and sub-folders in each of the 2 and 3 folders, but not the folders themselves inside w32x86, there may be other folders with names starting with “hewlett_packard”, “hphp” or something else; delete these folders also.
  7. Restart the print spooler (see steps 8 and 9 above)

At this point, the system should be pretty well back to the way it was before any printers were installed. Some would suggest restarting Windows at this point, but with Windows 2000 and later, this does not seem to be required.

 

 

Change the Printer Spooler Priority (Windows NT/2000/XP)

Normally the printer spooler runs at the same priority as other services on a system. If your system is being mainly used for printing or handles a large number of print jobs you can use this tweak to change the priority class the print spooler.

Open your registry and find or create the key below.

Create a new DWORD value, or modify the existing value, called “SpoolerPriority” and set it according to the value data below.

Exit your registry, you may need to restart or log out of Windows for the change to take effect.

 

(Default) REG_SZ (value not set)
SpoolerPriority REG_DWORD 0x00000001 (1)

 

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Print
 

 

Registry Settings
System Key: [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Print]
Value Name: SpoolerPriority
Data Type: REG_DWORD (DWORD Value)
Value Data: 0 = Normal priority, 1 = High priority, 0xFFFFFFFF = Idle priority

 

Troubleshooting Printers

 

Solution Title: Print Spooler Service won’t start – Windows XP

 

I can not print or add printers because the Print Spooler Service is not started.  The startup type is set to Automatic but it is not running.  When I try and start the service receive the following error:

Could not start the Print Spooler Service on Local Computer.  Error 1068: The dependency service or group failed to start.

The only dependency that I know of is Remote Procedure Call is is started.  I’m missing something but don’t know what it is.  Any help would be greatly appreciated.

 

Try this:
Click Start->Run->Services.msc
Locate the Printer Spooler service double-clicks it to get to the properties.
From the recovery tab, change all three options to “Restart the Service”.
Leave the bottom two options set to “1” Ok out of this dialogue.

Now go back and try to restart the service…

 

  1. About Ethernet?

 

Ethernet uses an access method called CSMA/CD. This is a system where each computer listens to the cable before sending anything through the network. If the network is clear, the computer will transmit. If some other node is already transmitting on the cable, the computer will wait and try again when the line is clear. Sometimes, two computers attempt to transmit at the same instant. When this happens a collision occurs. Each computer then backs off and waits a random amount of time before attempting to retransmit. With this access method, it is normal to have collisions. However, the delay caused by collisions and retransmitting is very small and does not normally affect the speed of transmission on the network. The Ethernet protocol allows for linear bus, star, or tree topologies. Data can be transmitted over twisted pair, coaxial, or fiber optic cable at a speed of 10 Mbps.

 

  1. About Fast Ethernet?

To increase transmission speed, the Ethernet protocol has developed a new standard that supports 100 Mbps. This is commonly called Fast Ethernet. Fast Ethernet requires the use of different, more expensive network concentrators/hubs and network interface cards. In addition, category 5 twisted pair or fiber optic cable is necessary.

 

  1. About Token Ring?

In Token Ring, the computers are connected so that the signal travels around the network from one computer to another in a logical ring. A single electronic token moves around the ring from one computer to the next. If a computer does not have information to transmit, it simply passes the token on to the next workstation. If a computer wishes to transmit and receives an empty token, it attaches data to the token. The token then proceeds around the ring until it comes to the destination computer. At this point, the data

is captured by the receiving computer. The Token Ring protocol requires a star-wired ring using twisted pair or fiber optic cable. It can operate at transmission speeds of 4 Mbps or 16 Mbps. Due to the increasing popularity of Ethernet, the use of Token Ring has decreased.

 

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  1. About Cabling?

In a twisted-pair network (10 Base T) each PC has a twisted-pair cable that runs to a centralized hub. Category 5 is the most reliable and widely compatible twisted-pair. It runs easily with 10Mbps or networks, and is required for Fast Ethernet. You can buy Category 5 cabling that is pre-made, or you can cut & crimp your own.

Category 5 cables can be purchased or crimped as either straight through or crossed. A Category 5 cable has 8 thin, color-coded wires inside that run from one end of the cable to the other. Only wires 1, 2, 3, and 6 are used by Ethernet networks for communication. Although only four wires are used, if the cable has 8 wires, all the wires have to be connected in both jacks.

Straight-through cables are used for connecting computers to a hub.

Crossed cables are used for connecting devices of similar type like hub-to-hub, switch-to-switch, etc

In a straight-through cable, also known as a patch cable, wires 1, 2, 3, and 6 at one end of the cable are also wires 1, 2, 3, and 6 at the other end. In a crossed cable, the order of the wires changes from one end to the other: wire 1 becomes 3 and 2 become 6.

To figure out which wire is wire number 1, hold the cable so that the end of the plastic RJ-45 tip, (the part that goes into a wall jack first), is facing away from you. Flip the clip so that the copper side faces up, (the springy clip will now be parallel to the floor). When looking down on the coppers, wire 1 will be on the far left.

 

  1. What is a layer 3 switch?

Layer 3 switches combine the speed and cost-effectiveness of switching, with the control and scalability of routing. Like a router, a Layer 3 switch runs routing protocols such RIP, RIP2, OSPF or any other routing protocol. The Layer 3 switch communicates with all other “routers” in the network. From a router’s perspective, it appears as if the Layer 3 switch is just another router exchanging information about topology and moving packets.

Unlike traditional routers a Layer 3 switch applies switching technologies in the forwarding plane. The main CPU does not inspect packets unless they are exceptions

 

  1. Difference between Router-Switch-Hub-Bridge?

 

Hubs work at the Physical layer. A hub is a totally dumb device. If it gets a data signal, it just forwards the signal to all devices. It cannot do any kind of filtering or addressing. Performance is not so good because a hub can’t establish a direct connection from one computer to another.

If a switch gets a data packet, it will try and find the destination device, and then send it to that device only, i.e. it establishes a point-to-point connection between the sending and receiving devices. But the devices must be on the same subnet. A switch won’t send data packet to computers on different subnets. A switch breaks up collision domains but it does not break up broadcast domains unless we use VLANs.

 Like Switches, Bridges operate at the Data Link layer and filter packets based on the MAC address. Generally bridges are used to extend the distance capabilities of the network while minimizing overall traffic, and switches are used mainly for their filtering capabilities to create multiple VLANs. Bridges have less number of ports than switches.

Routers work at the Network layer and operate on the IP Address. Router only gets a data packet if the destination computer isn’t on the same subnet or LAN. The router then finds the location of the destination device and then sends it in the right direction. A router breaks up broadcast domains.

 

  1. How is a full-duplex switch different from a switch?

A full duplex switch has one set of lines for receiving and one set of lines for transmitting, thus it can do both operations at the same time.

Connecting to a 2500 Router

Basically the router is connected from the console port

Use a rollover cable, the one supplied by Cisco is blue and flat, RJ-45 connectors.

Connect 1 end to the console port and the other to an RJ-45 to serial converter;

Plug that to the computers’ serial port

Then go to HyperTerminal

Select the COM port from connect using: probably COM2 or COM3

Change bits per second on the next screen to 9600 and click ok

You should be in the router if u did it correctly…

 

Picture of 2503 Router

 

  1. Difference between Firewall and Proxy?

 

 

  1. Layers in TCP/IP?

 

  • Process/Application Layer
  • Host-to-Host Layer
  • Internet Layer
  • Network Access Layer

 

  1. Difference between TCP and UDP?

 

  • TCP converts upper layer data in to segments and the segments are numbered and sequenced so that the destination TCP can place them in the same order, and can easily detect a missing segment. But in UPD data is broken in to segments and the segments are numbered but not sequenced.
  • TCP is connection oriented because it creates a virtual circuit between the source and destination before sending data. But UDP does not create any virtual circuit before sending data.
  • TCP uses acknowledgement to resent missing segments, but there is no acknowledgement in UDP.
  • So we can say TCP provide reliable communication but UDP provides unreliable communication.
  • Since TCP is creating virtual circuits, TCP is costly in terms of bandwidth. But UDP has low overhead

 

  1. Classes of IP Address?

       

 

 

  1. What is the Private IP Address range?

10.0.0.0 – 10.255.255.255

172.16.0.0 – 172.31.255.255

192.168.0.0 – 192.168.255.255

 

  1. How many bytes in an IPX network address?

80 Bits or 10 Bytes

 

  1. Different type of monitoring tools

Performance Monitor – Monitors network and computer statistics. Is able to log the data and export it for spreadsheet usage.

Network Monitor – Monitors network activity and is able to capture and look at packets of data sent over the network.

Netstat – Displays protocol statistics and current TCP/IP network connections. Netstat shows statistics since the server was booted.

 

  1. Network troubleshooting commands?

 

 

 

  1. What are some of the problems associated with operating a switched LAN?

Even though switch breakup collision domains it cannot break up broadcast traffic. Broadcasts, multicasts and slow convergence of spanning tree can cause problems.

 

  1. What is a Layer 4 Switch?

Layer 4 switches operate at the transport layer of the TCP/IP stack. Layer 4 switches operate at the UDP and TCP level, making switching decisions based on information held in the transport layer

 

  1. What is binding?

A process that establishes the initial communication channel between the protocol driver and the network adapter card driver

In a client/server system, a client transmits a request to a server, the server performs a processing operation, and the server returns a result. List all the possible things that can go wrong with transmission in this scenario.

  1. Request gets lost, client waits.
  2. Request gets temporarily lost, client sends another, and then two requests arrive at server.
  3. Results from server are lost.
  4. Results from server temporarily lost, then client sends request again, getting two sets of results.
  5. Client crashes before results come back.
  6. Server crashes before request arrives or after results start their way back.

 

  1. What is the difference between SSL and S-HTTP?

SSL: Secure Sockets Layer, a protocol developed by Netscape for transmitting private documents via the Internet. SSL works by using a private key to encrypt data that’s transferred over the SSL connection. Both Netscape Navigator and Internet Explorer support SSL and many Web sites use the protocol to obtain confidential user information, such as credit card numbers. By convention, Web pages that require an SSL connection start with https: instead of http:S-HTTP: Secure-HTTP is the protocol used for transmitting data securely over the World Wide Web Whereas SSL creates a secure connection between a client and a server, over which any amount of data can be sent securely, S-HTTP is designed to transmit individual messages securely. SSL and S-HTTP, therefore, can be seen as complementary rather than competing technologies. Both protocols have been submitted to the Internet Engineering Task Force (IETF) for approval as a standard

 

  1. What is Packet Switching?

Packet switching refers to protocols in which messages are divided into packets before they are sent.

Each packet is then transmitted individually and can even follow different routes to its destination. Once all the packets forming a message arrive at the destination, they are recompiled into the original message.

Most modern Wide Area Network (WAN) protocols, including TCP/IP, X.25, and Frame Relay, are based on packet-switching technologies.

The normal telephone service is based on a circuit-switching technology, in which a dedicated line is allocated for transmission between two parties. Circuit-switching is ideal when data must be transmitted quickly and must arrive in the same order in which it is sent. This is the case with most real-time data, such as live audio and video. Packet switching is more efficient and robust for data that can withstand some delays in transmission, such as e-mail messages and Web pages. A packet switched network is simply a digital data transmission network that uses packet switching technology.

 

  1. Firewalls – An overview

As the Name implies, firewalls are an electronic barrier designed to exclude unauthorized access to private networks. They come in various forms and different degrees of sophistication, depending on the size of the organization and the nature of the information stored.

Firewalls, both hardware and or software-based, primarily protect a network or central system from hacker intrusion from the Internet or other public network. In addition, some firewalls also restrict LAN user access to inappropriate websites. All networks with access to the Internet need a firewall.

 

How a Firewall works

  1. In the middle of the two networks sits a router.
  2. An access control list is placed on the router which has a list of IP addresses that can be allowed on to the network.
  3. When you try to access the network, the router automatically checks the list.
  4. If your IP address is one of those on the list, you’re allowed in. If not, you sit outside

 

Limitations of Firewalls

  • Firewalls must be updated with a list of inappropriate banned websites, as new sites appear very quickly.
  • Firewalls are not an effective protection against software viruses. We recommend that all users install anti–virus software.
  • Often Firewalls are positioned between an Internet router and the internal LAN, this result in a network bottleneck. Careful consideration should be paid to where a firewall is placed. We recommend that the firewall is installed between a switch and an Internet router.
  • Firewalls cannot protect against ‘back doors’, where a single network user has installed a separate Internet connection. To prevent this, companies should put an effective Internet access policy in place.
  • Equipped with the correct password, hackers can gain access to your network in spite of a firewall. To solve this, all passwords should be changed regularly

 

  1. In the TCP client-server model, how does the three-way handshake work in opening connection?

A: The client first sends a packet with sequence “x” to the server. When the server receives this packet, the server will send back another packet with sequence “y”, acknowledging the request of the client. When the client receives the acknowledgement from the server, the client will then send an acknowledgement back to the server for acknowledging that sequence “y” has been received.

 

  1. What is the purpose of exchanging beginning sequence numbers during the connection in the TCP client-server model?

To ensure that any data lost during data transfer can be retransmitted.

 

  1. What is HTTP Tunneling?

HTTP Tunneling is a security method that encrypts packets traveling thought the internet. Only the intended recipient should be able to decrypt the packets. It can be used to Create Virtual Private Networks. (VPN)

 

  1. Most Common Port Numbers

 

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