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List of Probable questions 1. What are the types of Operating System ? Real-time Operating System: It is a multitasking operating system that aims at executing real-time applications. Real-time operating systems often use specialized scheduling algorithms so that they can achieve a deterministic nature of behavior. The main object of real-time operating systems is their quick and predictable response to events. They either have an event-driven or a time-sharing design. An event-driven system switches between tasks based of their priorities while time-sharing operating systems switch tasks based on clock interrupts. Multi-user and Single-user Operating Systems: The operating systems of this type allow a multiple users to access a computer system concurrently. Time-sharing system can be classified as multi-user systems as they enable a multiple user access to a computer through the sharing of time. Single-user operating systems, as opposed to a multi-user operating system, are usable by a single user at a time. Being able to have multiple accounts on a Windows operating system does not make it a multi-user system. Rather, only the network administrator is the real user. But for a Unix-like operating system, it is possible for two users to login at a time and this capability of the OS makes it a multi-user operating system. Multi-tasking and Single-tasking Operating Systems: When a single program is allowed to run at a time, the system is grouped under a single-tasking system, while in case the operating system allows the execution of multiple tasks at one time, it is classified as a multi-tasking operating system. Multi-tasking can be of two types namely, pre-emptive or co-operative. In pre-emptive multitasking, the operating system slices the CPU time and dedicates one slot to each of the programs. Unix-like operating systems such as Solaris and Linux support pre-emptive multitasking. Cooperative multitasking is achieved by relying on each process to give time to the other processes in a defined manner. MS Windows prior to Windows 95 used to support cooperative multitasking. Distributed Operating System: An operating system that manages a group of independent computers and makes them appear to be a single computer is known as a distributed operating system. The development of networked computers that could be linked and communicate with each other, gave rise to distributed computing. Distributed computations are carried out on more than one machine. When computers in a group work in cooperation, they make a distributed system. Embedded System: The operating systems designed for being used in embedded computer systems are known as embedded operating systems. They are designed to operate on small machines like PDAs with less autonomy. They are able to operate with
a limited number of resources. They are very compact and extremely efficient by design. Windows CE, FreeBSD and Minix 3 are some examples of embedded operating systems. 2. Difference between FAT and NTFS.NTFS1)allows access local to w2k w2k3 XP win NT4 with SP4 & later may get access for somefile.2)Maximum size of partition is 2 Terabytes & more.3)Maximum File size is upto 16TB.4)File & folder Encryption is possible only in NTFS.FAT 321)Fat 32 Allows access to win 95 98 win millenium win2k xp on local partition.2)Maximum size of partition is upto 2 TB.3)Maximum File size is upto 4 GB.4)File & folder Encryption is not possible. 3. Enhancements in Windows 2003 from Windows 2000 4. Enhancements in Windows 2003 from Windows NT 5. What is Active Directory ?An active directory is a directory structure used on Microsoft Windows based computers andservers to store information and data about networks and domains. It is primarily used foronline information and was originally created in 1996. It was first used with Windows 2000.An active directory (sometimes referred to as an AD) does a variety of functions includingthe ability to provide information on objects, helps organize these objects for easy retrievaland access, allows access by end users and administrators and allows the administrator toset security up for the directory. 6. Types of FirewallNetwork-Level FirewallsThe first generation of firewalls (c. 1988) worked at the network level by inspecting packetheaders and filtering traffic based on the IP address of the source and the destination, the
port and the service. Some of these primeval security applications could also filter packetsbased on protocols, the domain name of the source and a few other attributes.Network-level firewalls are fast, and today youll find them built into most networkappliances, particularly routers. These firewalls, however, dont support sophisticated rule-based models. They don’t understand languages like HTML and XML, and they are capableof decoding SSL-encrypted packets to examine their content. As a result, they can’t validateuser inputs or detect maliciously modified parameters in an URL request. This leaves yournetwork vulnerable to a number of serious threats.Circuit-Level FirewallsThese applications, which represent the second-generation of firewall technology, monitorTCP handshaking between packets to make sure a session is legitimate. Traffic is filteredbased on specified session rules and may be restricted to recognized computers only.Circuit-level firewalls hide the network itself from the outside, which is useful for denyingaccess to intruders. But they dont filter individual packets.Application-Level FirewallsRecently, application-level firewalls (sometimes called proxies) have been looking moredeeply into the application data going through their filters. By considering the context ofclient requests and application responses, these firewalls attempt to enforce correctapplication behavior, block malicious activity and help organizations ensure the safety ofsensitive information and systems. They can log user activity too. Application-level filteringmay include protection against spam and viruses as well, and be able to block undesirableWeb sites based on content rather than just their IP address.If that sounds too good to be true, it is. The downside to deep packet inspection is that themore closely a firewall examines network data flow, the longer it takes, and the heavier hityour network performance will sustain. This is why the highest-end security appliancesinclude lots of RAM to speed packet processing. And of course youll pay for the addedchips.Stateful Multi-level Firewalls - SML vendors claim that their products deploy the bestfeatures of the other three firewall types. They filter packets at the network level and theyrecognize and process application-level data, but since they dont employ proxies, theydeliver reasonably good performance in spite of the deep packet analysis. On the downside,they are not cheap, and they can be difficult to configure and administer. 7. Difference between Hardware and Software Firewall.Hardware FirewallsYou can buy a hardware firewall as a stand-alone product, but more recently hardwarefirewalls are typically found in broadband routers, and should be considered an importantpart of your system and network set-up, especially for anyone on a broadband connection.Hardware firewalls can be effective with little or no configuration, and they can protectevery machine on a local network. Most hardware firewalls will have a minimum of four
network ports to connect other computers, but for larger networks, business networkingfirewall solutions are available.A hardware firewall examines data packet to determine their source and destination. Itcompares this information to a set of predefined or user-created rules that determinewhether the packet should be routed to its destination or blocked and dropped.A person with general computer knowledge can plug in a firewall, adjust a few settings andhave it work. To ensure that your firewall is configured for optimal security and protecthowever, you should learn its specific features, how to use them, and how to test thefirewall to make sure its protecting your network.Not all firewalls are created equal, and its important to read the manual anddocumentation. Additionally the manufacturers Web site usually provides a knowledgebaseor FAQ to help you get started. If the terminology is a too tech-oriented, you can also usethe Webopedia search to help you get a better understanding of some of the computerterms you will encounter while setting up your hardware firewall.To test your hardware firewall security, you can purchase third-party test software or searchthe Internet for a free online-based firewall testing service. Firewall testing is an importantpart of maintenance to ensure your system is always configured for optimal protection.Software FirewallsMost people prefer a software firewall. You install a software firewall on individualcomputers (just like any software), and you can customize its function and protectionfeatures. A software firewall protects your computer from outside attempts to control orgain access your computer, and, depending on which firewall you choose, it could alsoprovide protection against the most common Trojan programs or e-mail worms.Many software firewalls have user-defined controls for setting up safe file and printersharing and to block unsafe applications from running on your system. Additionally,software firewalls may also incorporate privacy controls, Web filtering (i.e., making certaintypes of sites – adult content, gambling, shopping, for example -- inaccessible) and more.The downside to software firewalls is that they only protect the computer they are installedon, not a network, so each individual computer needs to have a software firewall installedon it.Like hardware firewalls, there is a vast number of software firewalls from which to choose.To get started you may wish to read reviews of software firewalls and search out theproduct Web site to glean some information first. Because your software firewall will always
be running on your computer, you should make note of the system resources it requires andany incompatibilities with your operating system. A good software firewall will run in thebackground on your system and use only a small amount of system resources. Itsimportant to monitor a software firewall once installed and to download any updatesavailable from the developer.The best way to protect your computer and network is to use both types of firewalls, aseach offers different but much-needed security features and benefits. Updating your firewalland your operating system is essential to maintaining optimal protection, as is testing yourfirewall to ensure it is connected and working correctly. 8. Name the seven layers of OSI model.Layer 7:Application LayerDefines interface to user processes for communication and data transfer in networkProvides standardized services such as virtual terminal, file and job transfer and operationsLayer 6:Presentation LayerMasks the differences of data formats between dissimilar systemsSpecifies architecture-independent data transfer formatEncodes and decodes data; Encrypts and decrypts data; Compresses and decompressesdataLayer 5:Session LayerManages user sessions and dialoguesControls establishment and termination of logic links between usersReports upper layer errorsLayer 4:Transport LayerManages end-to-end message delivery in networkProvides reliable and sequential packet delivery through error recovery and flow controlmechanismsProvides connectionless oriented packet deliveryLayer 3:Network LayerDetermines how data are transferred between network devices
Routes packets according to unique network device addressesProvides flow and congestion control to prevent network resource depletionLayer 2:Data Link LayerDefines procedures for operating the communication linksFrames packetsDetects and corrects packets transmit errorsLayer 1:Physical LayerDefines physical means of sending data over network devicesInterfaces between network medium and devices 9. How to enable Firewall in Windows XP. A. Click Start, Control Panel, double–click Network Connections, right-click the desired connection, Properties, Advanced tab, Under Internet Connection Firewall, uncheck or check the Protect my computer and network by limiting or preventing access to this computer from the Internet check box. 10. How to Disable Firewall in Windows XP 11. Minimum System requirement of Windows XP, Vista, 2003 and 2008 12. Explain ping command.Ping is a basic Internet program that allows a user to verify that a particular IP addressexists and can accept requests.Ping is used diagnostically to ensure that a host computer the user is trying to reach isactually operating. Ping works by sending an Internet Control Message Protocol (ICMP) EchoRequest to a specified interface on the network and waiting for a reply. Ping can be used fortroubleshooting to test connectivity and determine response time. 13. pst file locationWin xp – c:doc & setting user name Local SettingsApplication DataMicrosoftOutlook 14. What is a port number ? a port number is part of the addressing information used to identify the senders and receivers of messages. Port numbers are most commonly used with TCP/IP connections 15. Where is the HOSTS file located C: windows system32driversetc
16. Lan cable code – Straight – 1. White orange 2. Orange 3. White green 4. Blue 5. White blue 6. Green 7. White brawn 8. Brawn Cross - 1–3 2-6 3–1 4–4 5–5 6–2 7–7 8 – 8.17. type of backup – Normal. - When an administrator chooses to use a normal backup, all selected files and folders are backed up and the archive attribute of all files are cleared. A normal backup does not use the archive attribute to determine which files to back up. A normal backup is used as the first step of any backup plan Copy. - Copy backup is a backup that copies all selected files but does not mark each file as having been backed up. In other words, the archive attribute is not cleared. Copying can be
carried out between normal and incremental backups because copying does not affect these other backup operations. Incremental. - A backup of those files which have changed since the last backup of any type. An incremental backup is the fastest backup and requires the least storage space on the backup media. However, incremental backups also require the longest time and many tapes to restore. Differential - A backup of those files which have changes since the last full backup. Should be performed at regular intervals. Daily. - Daily backup refers to making daily copies of data so that these additional copies may be used to restore the original after a data loss event. Daily backups can also be combined with weekly or monthly full backups, according to the backup scenario used 18. command to create domain – dcpramo.The Active Directory Database is Stored in %SYSTEM ROOT%NDTS folder. the activedirectory uses the sysvol folder as wellThe file is called as ntds.dit. Along with this file there are other files also present in this folder.The files are created when you run dcpromo.What is DNS?Domain Name System (DNS) is a database system that translates a computers fully qualifieddomain name into an IP address.
19.20. Explain different RAID levels21. Explain APIPA, IP address and Subnet mask22. Difference between IP v4 and IP v623. How to remove virus from a computer24. How to make a computer run faster25. What is attrib command ?26. What is edit command ?27. How to copy a file or folder using copy command28. How to format the hard disk using command line utilities29. Explain Cookies30.31. How to boot the computer in Safe mode32. What is Disk clean up, Disk Defragmentation, Device manager and System Restore33. USB port Vs Firewire port34. How to install a printer in Windows XP35.36. Explain mkdir, rmdir and chdir commands37. Types of hard disk38. Difference between primary and secondary partition39. Types of back in Window OS40. Differential Backup Vs Incremental Backup Vs Copy backup41. What is remote desktop.42. Recovery Console Vs Automated System Recovery43. What is NTLDR file44. How to tackle "missing NTLDR file" error45. How many bytes are there in MAC address46. Range of Class A IP address47. Range of Class B IP address48. Range of Class C IP address49. Default subnet mask of Class A, Class B and Class C IP address50. What is BSOD (Blue Screen of Death) and how to overcome it51. Difference between Preferred DNS and Alternate DNS server52. Transmission speed of T1 carrier