Sunday, August 14, 2011

Desktop Support Interview Related Q&A


I launch IE and i get a message telling me that my active x controls are disabled. How do i re enable them?
Answer: IE tools from menu bar -> internet options - advanced tab - >security --->
Follow on question > if the button to customize the active x control is grayed out, why may this be? Answer: There may be a local machine or domain policy in place to disable any active x controls or insufficient permission to change.
Where do you enter the details for automatic config scripts in IE?
Answer:  IE tools from menu bar -> options -> connections tab-> settings *my excel starts up, starts loading the plug-ins and freezes.
How would you go about fixing this?
Answer: press windows key + r to bring up the run dialog - or start then -> run type: excel /safe if excel starts in safe mode, then you can go through the administrative parts of the program to try and make necessary changes remove or disable plugins causing problem. Once done, exit excel and reboot the system then try running excel normally. Here is a good web site for excel i found helpful - > bo's excel tips & tricks page 6
If my blackberry stopped receiving emails, how would you go about resolving this?
Question to person asking question? Are we using the redirector or blackberry enterprise server or is there another service being used to relay messages? Possible answers: if redirector - verify the service is started on the machine that is setup to forward messages to the clients if black berry enterprise server - verify all services on the for the black berry enterprise server are started and running - verify also all other clients are not getting messages - the server may just need to be restarted or rebooted... If this is an outside service verify there are not service outages or problems with the outside service provider if no problems with the outside provider it could be some other changes to the account settings for the client have changed in some way.
What percentage of importance would you say customer service skills and technical skills have?
Answer: 100% all the time they are equally important and essential in customer satisfaction and job performance.
How else (other than joining a pc to the domain) can i get the machine name in the domain?
Answer:  ipconfig /all will display the host name - see explanation for - get mac address for machine.
My pst is corrupt and cannot be repaired, what do you do?
Answer:  If scanpst does not work from outlook then there are some low cost 3rd party utilities that i have used to repair a corrupted pst - I would research and use one of these utilities to fix the problem.
Name another way of joining a pc to domain?
Answer:  Right click on my computer - then properties - select the computer name tab - see: gateway support - joining a domain (for more detail)
A manager cannot print to network printer but all other users can, what do you do?
Answer:  Ask him to check of the printer is greyed out - or offline - to do this right go to start - then printers and faxes - click on printer to highlight - right click - verify printer is online and set for the default printer.
What is the printer registry file name?
Answer: printers additional answers: area used before printing actual print job? is spooler where jobs are spooled to the disk device before printing - server work spool locations can be found in the registry at hkey local machine -> system -> current control set -> control -> - print - defaultspooldirectory - this is where the key can be modified to change the print spooler to another disk drive or location - if needed, for performance issues or disk space issues.
What is the service used to print the jobs?
Print spooler - if no one can print to any job - check the print spooler and verify it is running to do this go to start then run type the following in the run command line - services.msc - then look for the print spooler service - if it states running and no one can print - try stopping and restarting the service chances are it is hung up.
Name 5 reasons why a user might not be able to logon to the network?
Answers: 1:  verify tcp/ip settings are correct - computer may not have the same tcp/ip address as the current network to log on to - make sure you can ping the domain controller by name and ip address also verify that you can ping the gateway address of the router.
2: Check account could be locked out, disabled or password changed also check to be sure computer account is not disabled.
3: Verify TCP/IP stack is working - ping 127.0.0.1 also verifies network cable is plugged in and port is active.
4: verify there is not port security setup on switch this could stop a computer from logging on to the network if it was moved from one location to another.
Explain how DHCP works?
DHCP - Dynamic Host Configuration Protocol
DHCP allows a computer to join an IP-based network without having a pre-configured IP address. DHCP is a protocol that assigns unique IP addresses to devices, then releases and renews these addresses as devices leave and re-join the network.
The process of assigning the IP addresses by the DHCP server also known as DORA (Discover Offer Request and Acknowledgement).
DORA process in DHCP
DHCP (D)iscover | DHCP (O)ffer | DHCP (R)equest | DHCP (A)ck
Step 1: Your computer sends a "Discovery" request asking for its IP information from any
Listening DHCP servers.
Step 2: Any listening DHCP servers will "Offer" their configuration information to your workstation.
Step 3: You workstation chooses the best lease then "Requests" that lease from the
Corresponding  DHCP server.
Step 4: The DHCP server you requested the IP configuration information from then
"Acknowledges" your request and leases you the IP configuration information.
A user has a laptop that runs fast on the network (at work) but slow at home? Explain what could be the problem?
Answer:  The computer may be attempting to use resources or map resources that have been allocated or supplied by the domain - this could include any set policies for a machine or user. - tell the client to connect to the vpn and then see if the problem remains the same.
Explain how to share outlook calenders and the type of permissions you need to assign.
A user can log on to the network but has no internet connection? Explain what could be the problem.

A user’s application on their desktop is not working; explain what you would do to resolve this problem

What is the difference between a unc and drive mapping?

How do you import external data into an excel spreadsheet?
What is a mail merge and how does it work?

Explain what tcp/ip is and how it works?
TCP/IP stands for "Transmission Control Protocol/Internet Protocol." Without getting too technical, it's the leading method for allowing two computers to talk to each other over a network (such as the internet).

TCP/IP has four layers. Programs talk to the Application layer. On the Application layer you will find Application protocols such as SMTP (for e-mail), FTP (for file transfer) and HTTP (for web browsing). Each kind of program talks to a different Application protocol, depending on the program purpose.
After processing the program request, the protocol on the Application layer will talk to another protocol from the Transport layer, usually TCP. This layer is in charge of getting data sent by the upper layer, dividing them into packets and sending them to the layer below, Internet. Also, during data reception, this layer is in charge of putting the packets received from the network in order (because they can be received out-of-order) and also checking if the contents of the packets are intact.
On the Internet layer we have the IP (Internet Protocol), which gets the packets received from the Transport layer and adds virtual address information, i.e., adds the address of the computer that is sending data and the address of the computer that will receive this data. These virtual addresses are called IP addresses. Then the packet is sent to the lower layer, Network Interface. On this layer packets are called datagrams.
The Network Interface will get the packets sent by the Internet layer and send them over the network (or receive them from the network, if the computer is receiving data). What is inside this layer will depend on the type of network your computer is using. Nowadays almost all computers use a type of network called Ethernet (which is available in several different speed grades; wireless networks are also Ethernet networks) and thus you should find inside the Network Interface layer the Ethernet layers, which are Logic Link Control (LLC), Media Access Control (MAC) and Physical, listed from up to bottom. Packets transmitted over the network are called frames.
Laptop questions
1) A user operating his laptop from home finds it very slow, but when using the laptop at the office is very fast. What could the possible reasons be while it was slow at home?
2) A manager takes his laptop abroad and operates it with no problem using his mobile. Once he gets back the uk his modem no longer works. What could the possible reasons for this be?
What could be the cause of an error stating that ntldr is missing when trying to boot?
Answer: Check to verify the system is not attempting to boot from another device - like a floppy or cd - if this is not the case - it could be a defective boot partition, bad disk boot sector or virus has attacked the boot sector usually track 0 of the hard drive.

What is the file extension for an excel add-in file?
Answer - .xll - see : file extension .xll - excel add-in files - (for more information)
What is the difference between a .pst file and a .ost file? - (same as above: - see previous question)
How would you obtain the mac address from a machine?
Answer: go to start the run type in the command line - cmd - this will bring to a dos prompt on the dos command prompt type in the following command ipconfig /all - this will show you the mac address for the machine and some other important ip information.
A blackberry user is abroad and is not receiving e-mails, he notices that he has gprs in lowercase on his device. What can be done to fix this problem?
Answer: From what i see on research it could be the service is not working correctly or possibly blocked by a firewall, it could even be the firmware on the device needs to be upgraded. I would contact the service provider to completely verify the error on this device.
Explain how dhcp works?
answer: dhcp assigns a client an ip address from a range of selected allocated addresses configured on the dhcp server - when a pc, client or device needs an ip address on the network it sends out an dhcpdiscover broadcast to find a dchp server the dhcp server the authoritive dhcp server for the network will then sends back to the client the dhcpoffer back to the client. - (if there are more then one dhcp server on a network then it is the first offer back to the client the client accepts the ip address) to see what dhcp server assigned the dhcp address to the client - command line - ipconfig / all here is the long version - article - microsoft corporation
How does dhcp work?
Answer - below: for dhcp to work properly, you must have at least one dhcp server and one dhcp client on your network. You'll also need a range of tcp/ip addresses to assign, as well as the gateway addresses and your subnet mask. Fortunately, windows nt comes with dhcp support as part of its available services. Most of the workstations on your system probably already support dhcp. Dhcp support also comes as part of windows 95 and 98, os/2 warp 4, macos 7.x and 8.x, and linux. You can even employ dhcp support on windows 3.11 for workgroups workstations. During start-up, a dhcp client workstation gets its tcp/ip addressing information from the server. Keep in mind that this address isn't permanent; the dhcp server simply gives the client an address "lease" that can expire and must be renewed on a regular basis. Your workstation obtains and maintains its address leases through several handshaking phases known as states. The workstation dhcp states include: • initialization • selection • requesting • binding • renewal • rebinding during initialization, the client boots normally until it needs a tcp/ip address. The client then loads an empty tcp/ip address and broadcasts a dhcpdiscover packet across the network. The dhcpdiscover packet contains the workstation's name and media access control (mac) address and can also contain the last tcp/ip address the client obtained from the server. With this information, the server may be able to give the client the same address it received on its last request. When an active dhcp server hears the dhcpdiscover packet, the selection state begins. The server reserves an address from its list and broadcasts a response to the workstation. The response, called a dhcpoffer packet, contains a proposed tcp/ip address for the workstation along with the workstation's mac address, subnet mask information, length of lease, and the tcp/ip address of the dhcp server making the offer. Note: just as a workstation does with the dhcpdiscover packet, a dhcp server must broadcast over the network to reach the requesting client. Both systems must start with mass broadcasts because tcp/ip isn't configured yet on the client to allow point-to-point communication. If the client doesn't receive a dhcpoffer packet at startup, it tries up to four more times over a five-minute period. The four retries occur randomly but are based on a loose pattern. The client retries each of the four attempts at 2-, 4-, 8-, and 16-second intervals with a random time between 0 and 1000 milliseconds tacked on to each try. If the workstation never receives a response, it waits five minutes and the process begins again. After the client receives a dhcpoffer packet, the requesting state begins. The client generates a dhcprequest packet, which accepts the tcp/ip address offered by the server that issued the dhcpoffer packet. The dhcprequest packet includes the tcp/ip address of the server that provided the client address. If the client needs any additional configuration information, such as a default gateway, wins, or dns addresses, it includes the request in the packet. If you have more than one dhcp server on your network, your client may receive more than one dhcpoffer packet. If this happens, the client will choose one of the offers and discard the rest. (the client typically selects the first offer received, but this is not always the case.) to wrap up the requesting state, the client issues a mass broadcast of the dhcprequest packet. All dhcp servers on the network receive the packet and compare its server address information to their own address. If the server's address doesn't match the one in the packet, then the server releases the address it had reserved for the client in its own specific dhcpoffer packet. If a server finds its own tcp/ip address in the dhcprequest packet, it responds to the client with a dhcpack packet. This packet contains the lease for the client as well as additional information the client requested. When the client receives the dhcpack packet, it begins the binding phase by binding the assigned address to the tcp/ip protocol running on its network card and then finishes booting. At this point, the client can communicate on the network using tcp/ip. The client keeps the tcp/ip address assigned to it for the length of its lease which you can adjust, or until you manually shut it off. If you keep the client running continually, it will eventually reach the end of its lease period. When the client reaches 50 percent of its assigned lease time, it will enter the renewal phase. The client sends a dhcprequest packet directly to the server that gave it its tcp/ip address. The dhcp server renews the lease and sends back a dhcpack packet, which contains the new lease and any configuration information that may have changed since the initial lease. If the client can't communicate with the server that granted its lease, it will display an error but continue to operate normally. When 87.5 percent of the client's lease time expires, the client begins to panic and enters the rebinding phase. During the rebinding phase, the client begins broadcasting dhcprequest packets across the network to any dhcp server that will respond to it. The current dhcp server may respond with a dhcpack packet that allows the client to continue using the address it was assigned initially. Or it may send a dhcpnak packet, which forces the client to reinitialize tcp/ip and obtain a new tcp/ip address and lease. If it accepts the dhcpnak packet, the client begins the whole process again at the initialization phase. If the client can't reach a dhcp server by the time its lease expires, it must stop using its assigned tcp/ip address. At this point, it can no longer communicate with other workstations on the network using tcp/ip. However, it can enter the initialization phase again and start broadcasting dhcprequest packets in an attempt to get a new lease.
A user can log on to the network but has no internet connection? Explain what could be the problem. There could be a security policy in place to stop that user from getting access to the internet you can check the policy's applied to the computer by typing on the start run command line rsop.msc it is also possible the client machine does not have the correct gateway address configured. If you can access the internet web pages by ip and not by name it is possible dns is not working correctly, try to ping the known gateway address of the network router if successful then try to ping 4.2.2.2 this is an internet address.
How would you alter auto recovery to save every 5 mins instead of every 10?
Answer: tools / other / save if a customer’s blackberry stopped syncing their calendar wirelessly, what would you do? answer: if all other wireless services are working - ie contacts and email then check sync settings and verify calendar is set to sync if a customer deleted a mail from his blackberry, but it did delete from his mailbox, how would you resolve this?
The deputy equities manager demands access to a legal shared drive, as he does not have the correct permissions, it is late at night and you are the only one left in the office what would you do? Follow on: if the decision makers are unreachable, what would you do? If the deputy equity manager tells you a multi-million pound contract depends on him getting access to this shared drive, what would you do ? If he then gets the equities manager who starts shouting at you and threatening to get you the sack, what would you do ? Hope some of these will help you and anyone else out there.
What is DNS?
Domain Name System (DNS) is a database system that translates a computer's fully qualified domain name into an IP address.
Networked computers use IP addresses to locate and connect to each other, but IP addresses can be difficult for people to remember. For example, on the web, it's much easier to remember the domain name www.amazon.com than it is to remember its corresponding IP address (207.171.166.48). DNS allows you to connect to another networked computer or remote service by using its user-friendly domain name rather than its numerical IP address. Conversely, Reverse DNS (rDNS) translates an IP address into a domain name.
Each organization that maintains a computer network will have at least one server handling DNS queries. That server, called a name server, will hold a list of all the IP addresses within its network, plus a cache of IP addresses for recently accessed computers outside the network. Each computer on each network needs to know the location of only one name server. When your computer requests an IP address, one of three things happens, depending on whether or not the requested IP address is within your local network:

0.0.0.0. Are reserved as N/W ID.
255.255.255.255 is reserved as broadcast ID.
127.0.0.1 Is reserved as loop back ID
 OSI Layers: 
           
Think of the seven layers as the assembly line in the
computer. At each layer, certain things happen to the data that prepare it for the next layer. The seven layers, which separate into two sets, are:
  • Application Set
  •  
    • Layer 7: Application - This is the layer that actually interacts with the operating system or application whenever the user chooses to transfer files, read messages or performs other network-related activities. Eg : NFS, FTP, SMTP, DNS

    • Layer 6: Presentation - Layer 6 takes the data provided by the Application layer and converts it into a standard format that the other layers can understand.
Eg : JPEG, GIF, ASCII
    • Layer 5: Session - Layer 5 establishes, maintains and ends communication with the receiving device.
Eg: SQL, RPC, Net biosnames.
  • Transport Set
    • Layer 4: Transport - This layer maintains flow control of data and provides for error checking and recovery of data between the devices. Flow control means that the Transport layer looks to see if data is coming from more than one application and integrates each application's data into a single stream for the physical network.
                                   Eg :  TCP, UDP ,SPX
    • Layer 3: Network - The way that the data will be sent to the recipient device is determined in this layer. Logical protocols, routing and addressing are handled here.
                                       Eg : IP, IPX, Appletalk
    • Layer 2: Data - In this layer, the appropriate physical protocol is assigned to the data. Also, the type of network and the packet sequencing is defined.
                                 Eg : Frame reply , PPP, Token ring,  IEEE 802.2, IEEE 802.3
    • Layer 1: Physical - This is the level of the actual hardware. It defines the physical characteristics of the network such as connections, voltage levels and timing.
                                            Eg : Ethernet, RJ 45
https://lh4.googleusercontent.com/VqYuiyGGFEV9LmtebIj1AdpdjV4tc-OTtX6lNJn47ZaYmHHuCF_zRGilrw1pWp5BVvfOWjQhKrfoxdt9L-yKLz6iJnAFxafMCXqrq9GiGznpSNp3meQ*
The seven layers of the OSI Reference Model

The OSI Reference Model is really just a guideline. Actual protocol stacks often combine one or more of the OSI layers into a single layer.
Where do we use cross and standard cable?
Computer to computer ==> cross
Switch/hub to switch/hub ==>cross
Computer to switch/hub ==>standard

127.0.0.1 is the loopback address in IP. Packets sent to this address do not actually travel onto the network, they automatically get routed to a receive queue on the local device. The loopback address is useful for testing network software when a working network connection is not present.

TCP                                             UDP
FTP         20, 21                          DNS                 53
Telnet   23                                 DHCP               67,68
SMTP    25                                 TFTP                69
DNS       53                                 NTP 123
HTTP      80                                 SNMP             161
POP       110                        
NNTP    119                        
HTTPS   443                        

Networking devices:
Hubs, Switches, Routers and NICs.
HUB: Hub is a centralized device provides communication among systems when we have more than 2 computers we need to have a device called hub to interconnect.
Disadvantage of a Hub:
When we want to transfer some data from one system to another system.
If our network has 24 systems the data packet instead of being sent only to the destined system it is being send to all the network participants. (i.e. 24 systems.)
Hubs follow broadcasting
SWITCH: It is an advanced version over a Hub.
The main benefit of switch is Unicast. Data packets are transmitted only to the target computer instead of all.
Switch maintains a table called MIT (Mac Information Table.) which is generated as soon as we turn on the switch, which acts like an index table and easy the process of finding the networked system. MIT contains the port no, IP address and MAC address.
MAC: (Media Access Control): It is an address burnt in the NIC by the manufacturer.
MAC address is of 48 bits in the farm of Hexa decimal.
Every NIC has its own unique MAC address.
MAC address determines the physical location of a system.
ROUTER: Router is a device connects two different networks.
                Class A network with Class C network etc.
Routing is a process of communication between two different networks.
Network Topologies:
The way of cabling is called topology.
The architecture of a network is called topology
E.g.: Bus, Star, Ring, and Mesh Topologies.
Bus Topology:
Components of Bus Topology:
  1. Co-axial cable (back bone cable)
  2. T- connectors
  3. BNC (British Network Connector)
  4. Terminator
  5. Patch cable
Disadvantages of Bus:
 If anything goes wrong with backbone cable whole network is down.
Follows a serial communication.
Outdated these days.
Star Topology:
Star topology is an advanced version over bus topology. Where it uses either a hub or a switch, it uses cat5/6 cables.
It uses connecters called (Recommend Jack) - RJ45
Star topology offers faster data transfer or processing.
Ring Topology:
Ring topology is useful when we want redundancy (fault tolerance) we go with this type of topology.
Ring topology uses a device called MSAU. (Multi Station Access Unit)
It is a unit inside which a logical ring is formed. This ring ensures the availability of Network. The availability of ring ensures availability of network.
It was basically implemented in IBM networks.
AD: Is a centralized database where it contains the information about the objects like users, groups, computers, printers etc.
AD is a centralized hierarchical Directory Database.
AD is a searchable Database.
2003 O/S. when installed (gets installed as a stand alone server) to promoting to    D.C. We have to install A.D.

Domain Controller (D.C.)
A server where A.D. is installed is called D.C.
Functionality of A.D.:
Using A.D. we can organize, manage and control resources.
It provides single point of administration.
Purpose of A.D.:
  1. Provides user logon authentication services.
  2. To organize and manage user A/Cs, computers, groups and n/w resources.
  3. Enables authorized users to easily locate n/w resources.

Group Policy:
It is a feature of 2000&03 with which an administrator can have full control on users and computers. Using group policy we can implement security, policies, software deployment, folder redirection, Internet explorer maintenance.
Group policies enable the users either to access or to be denied of an object. Group policy can be implemented on computers &users.
Group Policy Object (GPO)
GPO defines polices implemental for the objects. One group policy object can be linked with multiple objects like site, domains, DCs, OUs, etc…
The order in which the group policy is applied.
Virtualization allows users to consolidate physical resources, simplify deployment and administration, and reduce power and cooling requirements.  While virtualization technology is most popular in the server world, virtualization technology is also being used in data storage such as Storage Area Networks, and inside of operating systems such as Windows Server 2008 with Hyper-V.

Virtualization Advantages:
  • Server consolidation                                                    
  • Reduced power and cooling
  • Green computing
  • Ease of deployment and administration
  • High availability and disaster recovery
Popular virtualization products include:
  • VMware
  • Microsoft Hyper-V
  • Virtual Iron
  • Xen

·         NAT: It is a service of routing provides network address translation from private to public
·         When we have 2 networks public & private in order to protect private network from public network (intruders) we need NAT.
·         NAT enables one way communication. I.e. private network can communicate with public network but not vice versa.
A virtual private network (VPN) is a secure way of connecting to a private Local Area Network at a remote location, using the Internet or any insecure public network to transport the network data packets privately, using encryption. The VPN uses authentication to deny access to unauthorized users, and encryption to prevent unauthorized users from reading the private network packets. The VPN can be used to send any kind of network traffic securely, including voice, video or data.
If you want to uninstall an appliction that has no uninstall program and it is not listed in the Add/Remove applet of Control Panel
(or that uninstall doesn't work), then just delete the directory/files.
Start Regedit and drill down to :

HKEY_LOCAL_MACHINE\SOFTWARE\ and
HKEY_CURRENT_USER\SOFTWARE

locating the applications entry and delete them.

Use Explorer to to remove the entries from the Start Menu in either
C:\Documents and Folders\All Users\Start Menu\Programs\ and/or
C:\Documents and Folders\(your username)\Start Menu\Programs\

If there is an entry in the Add/Remove list, start regedit go to:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall
locate the entry and delete it.

If the app has a service, edit:
HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services
and scroll down till you locate it. Then delete it.

If this app starts automatically and there is no entry in the StartUp folder(s), then use Regedt32 to edit:

HKEY_CURRENT_USER\Software\Microsoft\WindowsNT\CurrentVersion\Windows
The Windows Registry is used as a single place to store much of the information and settings for software programs, hardware devices, user preferences, operating system configurations, and much more.
In many ways, the registry can be thought of as a kind of DNA for the Windows operating system



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