Active directory stores information about users, computers and network resources and makes the resources accessible to users and application with a single sign on Authentication.
Q) What is an Object?
An object is distinct set of attributes that represents a network resource (a user, a computer, a group policy, etc) and object attributes are characteristics of that object stored in the directory
Q) What is Organization Unit?
An organization unit is a versatile container object used to organize objects within a domain into logical administrative groups. These organization unit consist of sub-organization units
Q) What is domain?
Domain is a logical structured boundary in active directory, it is collection of hosts and sub-domains Domain contains information about all the objects it contains.
Domain provides functions like:
An Administrative boundary for objects
A means of managing security for shared resources
A unit of replication for objects
Q) What is Tree?
A tree is a grouping or hierarchical arrangement of one or more windows 2000/2003 domains that allow global resource sharing. We can create larger Trees but joining one or more domains.
Q) What is forest?
A collection of windows 2000 domains that does not necessarily share a common namespace, All of the domains within a forest share a common schema and Global catalog and resources can be shared between the domains in a forest. A Forest is a group of one or more trees.
FSMO: Flexible Single Master Operation Roles
Forest wide roles:
Schema Master Role: It contains master list of objects and classes and attributes that are user to create all active directory objects such as user, computer and printers.
Domain naming master:The active directory domain controller responsible for handling addition or deleting of domains within active directory,
There can be only one domain naming master in the entire forest at any time.
Domain wide roles:
Primary domain controller Emulator (PDC): The windows 2000 domain controller that is user primarily for backwards compatibility with widows NT domain controllers.
Relative Identifier master (RID):
The domain controller that is responsible for generating unique identifiers for each of the domains within an Active directory environment.
When a new object is created, the domain controller creates a new security principal that epresents the object and assigns that object a unique security identifier (SID), This SID consists of a domain SID, which is unique for each security principal created in the domain.
Infrastructure Master:
The windows 2000 domain controller that is responsible for managing group memberships and transferring this information to other domain controllers in the active directory environment
Q) Modes:
Mixed mode: Active directory mode that allows the use of windows NT domain controllers.
Native Mode:Windows 2000 native, you must have only Windows 2000 and Windows Server 2003 domain controllers. When running Windows 2000 native functional level, you have the added capabilities of
? Using universal security groups
? Nesting groups
? Using SID History
Q) What is Group policy?
Settings that can affect the behavior and the functionality available for user, computers or resources.
Q) What is DNS?
An internet host dedicated to the function of translating fully qualified domain names into IP addresses.
Q) What is DHCP?
It is a method of automatically assigning up address to client computers on a network.
Q) What is Global Catalog?
It is a search index which contains information about its domain and partial information of other domains.
Q) Active directory user which protocol
Kerberos Version 5
Q) Which protocol queries Active directory?
LDAP (lightweight directory protocol)
Port : 389
Ports:
FTP 21
SMTP25
POP3 110
Telnet 23
SSL443 (Secured socket layer)
LDAP 389
DNS 53
NetBIOS139
Kerberos WWW,88
Microsoft SQL server 1433
L2TP1701
UPD 5500
Q) How many ports are available?
65,536.
Q) How many Ports are used by Operating system?
1-1024 ports
Q) How will windows 98 and NT Authenticate to windows 2000 and 2003?
Clients have to be installed with “Directory services”
It user NTNL protocol (New Technology Lan Network)
Q) Name of active directory Database?
NTDS.dit
Q) What does Sysvol Contain?
Objects and Classes
Q) How will we restore Active Directory?
2 methods
1) Authoritative Restore
2) Non Authoritative Restore
In non-authoritative restore, the distributed services on a domain controller are restored from backup media and the restored data is then updated through normal replication.
An authoritative restore brings a domain or a container back to the state it was in at the time of backup and overwrites all changes made since the backup.
Backup of Active Directory
Preliminary Backup Tasks
The backup device is attached to a computer on the network and is turned on. If you are backing up to tape, you must attach the tape device to the computer on which you run Windows Backup.
Creating an Active Directory Backup
After you have completed the preliminary tasks, you can perform the Active Directory backup using the Backup or Restore Wizard.
Q) How do you install active directory?
DCPROMO
Differences between Windows 2000 and windows 2003?
Windows 2003 AD introduced a number of new security features, as well as convenience features such as the ability to rename a domain controller and even an entire domain – see Microsoft’s website for more details. Windows Server 2003 also introduced numerous changes to the default settings that can be affected by Group Policy – you can see a detailed list of each available setting and which OS is required to support it by downloading the Group Policy Settings Reference here (free download). ADS stand for Automated Deployment Services and is used to quickly roll out identically-configured servers in large-scale enterprise environments. You can get more information from the ADS homepage
What’s the difference between Windows XP Home and Professional editions?
Intended For
Windows XP only
Windows XP Professional Edition
Includes extended support for security between multiple users on the same machine.
Better support for peer-to-peer networking, plus support for joining a “Windows NT domain.”
The backup utlity is installed by default.
The Professional edition includes the following components not found in the Home edition:
Administrative Tools (in the Start Menu and Control Panel)
Automated System Recovery (ASR)
Boot Configuration Manager
DriverQuery
Group Policy Refresh Utility
Multi-lingual User Interface (MUI) add-on
NTFS Encryption Utility
Offline Files and Folders
OpenFiles
Performance Log Manager
Remote Desktop
Scheduled Tasks Console
Security Template Utility
Taskkill
Tasklist
Telnet Administrator
Provides support for multi-processor systems (2 or 4 CPUs), Dynamic Disks, Fax
Migration Tool for Windows NT to windows 2000
Q) DNS
Short for Domain Name System (or Service or Server), an Internet service that translates domain names into IP addresses. Because domain names are alphabetic, they’re easier to remember. The Internet however, is really based on IP addresses. Every time you use a domain name, therefore, a DNS service must translate the name into the corresponding IP address. For example, the domain name www.example.com might translate to 198.105.232.4.
The DNS system is, in fact, its own network. If one DNS server doesn’t know how to translate a particular domain name, it asks another one, and so on, until the correct IP address is returned.
DNS quires:
The major task carried out by a DNS server is to respond to queries (questions) from a local or remote resolver or other DNS acting on behalf of a resolver - a query would be somthing like ‘what is the IP address of host=fred in domain=mydomain.com’. There are three types of queries that DNS support:
1.A recursive query - the real answer to the question is always returned. DNS servers are not required to support recursive queries.
2.An Iterative (or non-recursive) query - where the real answer MAY be returned. All DNS servers must support Iterative queries.
Note: The process called Reverse Mapping does not use Inverse queries but instead uses recursive and non-recursive queries with the Special domain name IN-ADDR.ARPA.
Perform an Unattended Installation
The Remote Installation Server (RIS) server must have the RIS server software installed and configured. RIS clients are computers that have a Pre-boot eXecution Environment (PXE) network adapter or use a RIS boot disk. PXE is a technology that is used to boot to the network when no operating system or network configuration has been installed and configured on a client computer
The RIS clients access RIS servers through DHCP to remotely install the operating system from the RIS server. The network must have a DHCP server, a DNS server, and Active Directory to connect to the RIS server operating system.
ERD: Emergency Repair disk
Global group: An active directory security group that contains accounts only form its own domain
Global Unique Identifier (GUID):A special identifier that uniquely identifies an object within the active directory
ISDN: Integrated Services Digital Network: A direct, digital, dialup connection that operates at 64KB per channel over regular twisted pair cable.
MSI: A standard that is used to automatically deploy applications with windows installer packages.
NTUSER.Dat: The file that is created for a local user profile.
NTUSER.Man: The file that is created for Mandatory profile.
Router: A Network layer device that moves packets between netwoks. Router provides internet work connectivity.
SMTP: A TCP/IP based protocol that is primarily used for the exchange of internet emails, SMTP can also be used by the active directory to manage intersite replication between domain controllers.
Subnet: A collection of TCP/IP addresses that define a particular network location. All of the computer within subnet share same group of TCP/IP addresses and have the same subnet masking.
Subnet Masking: A number mathematically applied to IP addresses to determine while ip addresses are a part of the same sub-network as the computer applying the subnet masking
Q) What is Natting?
Nat is the translation of IP address from internet to local LAN and vice versa
NAT (Network Address Translation or Network Address Translator) is the translation of an Internet Protocol address (IP address) used within one network to a different IP address known within another network. It lets the company use a single IP address in its communication with the world.
Q) What is VPN?
A virtual private network (VPN) is a network that uses a public telecommunication infrastructure, such as the Internet, to provide remote offices or individual users with secure access to their organization’s network
It uses protocol called Layer Two Tunneling Protocol (L2TP).
Q) What is DNS?
The domain name system (DNS) is the way that Internet domain names are located and translated into Internet Protocol addresses. A domain name is a meaningful and easy-to-remember “handle” for an Internet address.
Q) What is Kerberos?
Kerberos is a secure method for authenticating a request for a service in a computer network.
Kerberos lets a user request an encrypted “ticket” from an authentication process that can then be used to request a particular service from a server. The user’s password does not have to pass through the network
Q) What is domain controller?
Primary domain controller (PDC) and backup domain controller (BDC) are roles that can be assigned to a server in a network of computers that use the Windows NToperating system.
A backup domain controller can step in as primary domain controller if the PDC server fails and can also help balance the workload if the network is busy enough.
Q) What is DHCP?
DHCP (Dynamic Host Configuration Protocol) is a communications protocol that lets network administrators centrally manage and automate the assignment of Internet Protocol (IP) addresses in an organization’s network.
q) What is Integrated zone?
This zone is integrated with AD database, its very secured bc AD maintains it and replication happens when AD replication happens.
RAID:
RAID (redundant array of independent disks; originally redundant array of inexpensive disks) is a way of storing the same data in different places (thus, redundantly) on multiple hard disks. By placing data on multiple disks
RAID-0: This technique has striping but no redundancy of data. It offers the best performance but no fault-tolerance.
RAID-1: This type is also known as disk mirroring and consists of at least two drives that duplicate the storage of data
Provides the best performance and the best fault-tolerance in a multi-user system.
RAID-5: This type includes a rotating parity array
Thus, all read and write operations can be overlapped. RAID-5 stores parity information but not redundant data.
I can’t seem to access the Internet, don’t have any access to the corporate network and on ipconfig my address is 169.254.*.*. What happened? The 169.254.*.* netmask is assigned to Windows machines running 98/2000/XP if the DHCP server is not available. The name for the technology is APIPA (Automatic Private Internet Protocol Addressing).
We’ve installed a new Windows-based DHCP server, however, the users do not seem to be getting DHCP leases off of it. The server must be authorized first with the Active Directory.
How can you force the client to give up the dhcp lease if you have access to the client PC? ipconfig /release
What authentication options do Windows 2000 Servers have for remote clients? PAP, SPAP, CHAP, MS-CHAP and EAP.
What are the networking protocol options for the Windows clients if for some reason you do not want to use TCP/IP? NWLink (Novell), NetBEUI, AppleTalk (Apple).
What is data link layer in the OSI reference model responsible for? Data link layer is located above the physical layer, but below the network layer. Taking raw data bits and packaging them into frames. The network layer will be responsible for addressing the frames, while the physical layer is reponsible for retrieving and sending raw data bits.
What is binding order? The order by which the network protocols are used for client-server communications. The most frequently used protocols should be at the top.
How do cryptography-based keys ensure the validity of data transferred across the network? Each IP packet is assigned a checksum, so if the checksums do not match on both receiving and transmitting ends, the data was modified or corrupted.
Should we deploy IPSEC-based security or certificate-based security? They are really two different technologies. IPSec secures the TCP/IP communication and protects the integrity of the packets. Certificate-based security ensures the validity of authenticated clients and servers.
What is LMHOSTS file? It’s a file stored on a host machine that is used to resolve NetBIOS to specific IP addresses.
What’s the difference between forward lookup and reverse lookup in DNS? Forward lookup is name-to-address, the reverse lookup is address-to-name.
How can you recover a file encrypted using EFS? Use the domain recovery agent.
What are the basic expansion card types?ISA and PCI, ISA can be used only on XT, AT and ATX boards. The industry now considers ISA obsolete.
How do you clear CMOS password? Since CMOS is a special chip with its own battery, the best way to clear out a CMOS chip is to disconnect it from its power supply.
Where does the Real mode on the CPU come from? The original 8086, which only had 1 MB of memory. This megabyte is split into low memory for IRQ tables, application memory and high memory.
Where does CPU Enhanced mode originate from? Intel’s 80386 was the first 32-bit processor, and since the company had to backward-support the 8086. All the modern Intel-based processors run in the Enhanced mode, capable of switching between Real mode (just like the real 8086) and Protected mode, which is the current mode of operation.
Name the processor lines of two major manufacturers? High-end: Intel - Pentium (II, III, 4), AMD - Athlon. Low-end: Intel - Celeron, AMD - Duron. 64-bit: Intel - Itanium 2, AMD - Opteron.
What’s the difference between L1 and L2 cache? Level 1 cache is internal to the chip, L2 is external.
What’s the speed and device maximum specs for Firewire? IEEE 1394 (Firewire) supports the maximum of 63 connected devices with speeds up to 400 Mbps.
Where’s MBR located on the disk? Main Boot Record is located in sector 0, track 0, head 0, cylinder 0 of the primary active partition.
What’s the maximum hard drive size for FAT16-based Windows system? 2 GB.
How many logical drives is it possible to fit onto a physical disk? Maximum of 24 logical drives. The extended partition can only have 23 logical drives.
WHat are * and ? when using them for wildcards in Windows? * - any characters, arbitrary amoung, ? - single character.
How does the browser know to go to a certain IP address when you enter a domain like google.com? It searches through local DNS cache, if nothing is there, it queries the ISP’s DNS server.
A: The layers are physical, data link, network, transport, session, presentation, and application layers.
Q: In the TCP client-servel 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 acknowledge back to the server for acknowledging that sequence “y” has been received.
Q: What is the purpose of exchanging beginning sequence numbers during the the connection in the TCP client-server model?
A: To ensure that any data lost during data transfer can be retransmitted.
Q: How does Asynchronous Transfer Mode (ATM) work?
A: ATM works by transmitting all traffic in small, fixed-sized cells. These small, fixed-size cells reduces queuing delay and can be switched quickly. ATM fits into layer 2 of the OSI model and provides functions for framing and error correction. At the port interface, ATM switches convert cells into frames, and vice versa. ATM provides Quality of Service and traffic shaping.
Q: Given a Class B Network with subnet mask of 255.255.248.0 and a packet addressed to 130.40.32.16, what is the subnet address?
A: Take the 2 addresses, write them in binary form, then AND them. The answer is 130.40.32.0
Q1. Name of seven layers in Open System Interconnection model.
A. They are Application, Presentation, Session, Transport, Network, Data link, and Physical.
Q2. What is the time complexity of matrix multiplication ?
void Mult_Matrix(matrix A, matrix B, matrix C)
{
int i, j, k;
for ( i = 1; i < N; i++)
for ( j = 1; j < N; j++ )
{
C[i][j] = 0;
for ( k = 0; k < N; k++ )
C[i][j] = A[i][j]*B[k][j];
}
retrun;
}
A. The time comlexity of matrix mulitiplication is O(N^3)
Q3. What is the null pointer in C++ ?
A. The null pointer is a special C++ pointer value that can be used for any pointer that doesn’t pointer anywhere. It can be written as the constant NULL form stlib.h
Q4. What is the goal of the shortest distance algorithm ?
A. The goal is to completely fill the distance array so that for each vertex v, the value of distance[v] is the weight of the shortest path from start to v.
Q5. What is the difference between an abstract class and an interface?
A. An abstract class may have fields and some implemented methods. An interface has no implementation; only constants and method declarations.
Question 1: How does the race condition occur?
It occurs when two or more processes are reading or writing some shared data and the final result depends on who runs precisely when.
Question 2: What is multiprogramming?
Multiprogramming is a rapid switching of the CPU back and forth between processes.
Question 3: Name the seven layers of the OSI Model and describe them briefly.
Physical Layer - covers the physical interface between devices and the rules by which bits are passed from one to another.
Data Link Layer - attempts o make the physical link reliable and provides the means to activate, maintain, and deactivate the link.
Network Layer - provides for the transfer of information between end systems across some sort communications network.
Transport Layer - provides a mechanism for the exchange of data between end system.
Session Layer - provides the mechanism for controlling the dialogue between applications in end systems.
Presentation Layer - defines the format of the data to be exchanged between applications and offers application programs a set of data transformation services.
Application Layer - provides a means for application programs to access the OSI environment.
Question 4: What is the difference between TCP and UDP?
TCP and UDP are both transport-level protocols. TCP is designed to provide reliable communication across a variety of reliable and unreliable networks and internets.
UDP provides a connectionless service for application-level procedures. Thus, UDP is basically an unreliable service; delivery and duplicate protection are not guareented.
Question 5: What does a socket consists of?
The combination of an IP address and a port number is called a socket.
You need to retrieve a file from the file server for your word processing application, which layer of the OSI model is responsible for this function?
Presentation layer
Application layer
Session layer
Transport layer
Datalink layer
You are working in a word processing program, which is run from the file server. Your data comes back to you in an unintelligible manner. Which layer of the OSI model would you investigate?
Application layer
Presentation layer
Session layer
Network layer
Datalink layer
The IEEE subdivided the datalink layer to provide for environments that need connectionless or connection-oriented services. What are the two layers called?
Physical
MAC
LLC
Session
IP
You are working with graphic translations. Which layer of the OSI model is responsible for code formatting and conversion and graphic standards.
Network layer
Session layer
Transport layer
Presentation layer
Which is the best definition of encapsulation?
Each layer of the OSI model uses encryption to put the PDU from the upper layer into its data field. It adds header and trailer information that is available to its counterpart on the system that will receive it.
Data always needs to be tunneled to its destination so encapsulation must be used.
Each layer of the OSI model uses compression to put the PDU from the upper layer into its data field. It adds header and trailer information that is available to its counterpart on the system that will receive it.
Each layer of the OSI model uses encapsulation to put the PDU from the upper layer into its data field. It adds header and trailer information that is available to its counterpart on the system that will receive it.
Routers can be configured using several sources. Select which of the following sources can be used.
ConsolePort
Virtual Terminals
TFTP Server
Floppy disk
Removable media
Which memory component on a Cisco router contains the dynamic system configuration?
ROM
NVRAM
Flash
RAM/DRAM
Which combination of keys will allow you to view the previous commands that you typed at the router?
ESC-P
Ctrl-P
Shift-P
Alt-P
Which commands will display the active configuration parameters?
show running-config
write term
show version
display term
You are configuring a router, which prompt tells you that you are in the privileged EXEC mode?
@
>
!
:
#
What does the command “IP name-server 255.255.255.255? accomplish?
It disables domain name lookup.
It sets the domain name lookup to be a local broadcast.
This is an illegal command.
The command is now defunct and has been replaced by “IP server-name ip any”
The following selections show the command prompt and the configuration of the IP network mask. Which two are correct?
Question 1: What is the major advantage of a hash table? (Asked by Silicon Magic Corp. people)
Answer: The major advantage of a hash table is its speed. Because the hash function is to take a range of key values and transform them into index values in such a way that the key values are distributed randomly across all the indices of a hash table.
Question 2: What are the techniques that you use to handle the collisions in hash tables?(Asked by Silicon Magic Corp. people)
Answer: We can use two major techniques to handle the collisions. They are open addressing and separate chaining. In open addressing, data items that hash to a full array cell are placed in another cell in the array. In separate chaining, each array element consist of a linked list. All data items hashing to a given array index are inserted in that list.
Question 3: In Unix OS, what is the file server? (Asked by Silicon Magic Corp. people)
Answer: The file server is a machine that shares its disk storage and files with other machines on the network.
Question 4: What is NFS? What is its job?(Asked by Silicon Magic Corp. people)
Answer: NFS stands for Network File System. NFS enables filesystems physically residing on one computer system to be used by other computers in the network, appearing to users on the remote host as just another local disk.
Question 5: What is CVS? List some useful CVS commands.(Asked by Silicon Magic Corp.people)
Anser: CVS is Concurrent Version System. It is the front end to the RCS revision control system which extends the notion of revision control from a collection of files in a single directory to a hierarchical collection of directories consisting of revision controlled files. These directories and files can be combined together to form a software release.
There are some useful commands that are being used very often. They are
LILO stands for Linux boot loader. It will load the MBR, master boot record, into the memory, and tell the system which partition and hard drive to boot from.
What is the main advantage of creating links to a file instead of copies of the file?
A: The main advantage is not really that it saves disk space (though it does that too) but, rather, that a change of permissions on the file is applied to all the link access points. The link will show permissions of lrwxrwxrwx but that is for the link itself and not the access to the file to which the link points. Thus if you want to change the permissions for a command, such as su, you only have to do it on the original. With copies you have to find all of the copies and change permission on each of the copies.
Write a command to find all of the files which have been accessed within the last 30 days.
find / -type f -atime -30 > December.files
This command will find all the files under root, which is ‘/’, with file type is file. ‘-atime -30? will give all the files accessed less than 30 days ago. And the output will put into a file call December.files.
What is the most graceful way to get to run level single user mode?
A: The most graceful way is to use the command init s.
If you want to shut everything down before going to single user mode then do init 0 first and from the ok prompt do a boot -s.
What does the following command line produce? Explain each aspect of this line.
A: First let’s dissect the line: The date gives the date and time as the first command of the line, this is followed by the a list of all running processes in long form with UIDs listed first, this is the ps -ef. These are fed into the awk which filters out all but the UIDs; these UIDs are piped into sort for no discernible reason and then onto uniq (now we see the reason for the sort - uniq only works on sorted data - if the list is A, B, A, then A, B, A will be the output of uniq, but if it’s A, A, B then A, B is the output) which produces only one copy of each UID.
These UIDs are fed into wc -l which counts the lines - in this case the number of distinct UIDs running processes on the system. Finally the results of these two commands, the date and the wc -l, are appended to the file “Activity.log”. Now to answer the question as to what this command line produces. This writes the date and time into the file Activity.log together with the number of distinct users who have processes running on the system at that time. If the file already exists, then these items are appended to the file, otherwise the file is created.
How do you list the files in an UNIX directory while also showing hidden files?ls -ltra
How do you execute a UNIX command in the background? Use the “&”.
What UNIX command will control the default file permissions when files are created?umask
Explain the read, write, and execute permissions on a UNIX directory. Read allows you to see and list the directory contents. Write allows you to create, edit and delete files and subdirectories in the directory. Execute gives you the permissions to run programs or shells from the directory.
What is the difference between a soft link and a hard link? A symbolic (soft) linked file and the targeted file can be located on the same or different file system while for a hard link they must be located on the same file system.
Give the command to display space usage on the UNIX file system.df -lk
Explain iostat, vmstat and netstat.iostat reports on terminal, disk and tape I/O activity. vmstat reports on virtual memory statistics for processes, disk, tape and CPU activity. netstat reports on the contents of network data structures.
How would you change all occurrences of a value using VI? %s/(old value)/(new value)/g
Give two UNIX kernel parameters that effect an Oracle install. SHMMAX & SHMMNI
Briefly, how do you install Oracle software on UNIX? Basically, set up disks, kernel parameters, and run orainst.
Explain hidden shares. Hidden or administrative shares are share names with a dollar sign ($) appended to their names. Administrative shares are usually created automatically for the root of each drive letter. They do not display in the network browse list.
How do the permissions work in Windows 2000? What permissions does folder inherit from the parent? When you combine NTFS permissions based on users and their group memberships, the least restrictive permissions take precedence. However, explicit Deny entries always override Allow entries.
Why can’t I encrypt a compressed file on Windows 2000? You can either compress it or encrypt it, but not both.
If I rename an account, what must I do to make sure the renamed account has the same permissions as the original one? Nothing, it’s all maintained automatically.
What’s the most powerful group on a Windows system? Administrators.
What are the accessibility features in Windows 2000? StickyKeys, FilterKeys Narrator, Magnifier, and On-Screen Keyboard.
Why can’t I get to the Fax Service Management console? You can only see it if a fax had been installed.
What do I need to ensure before deploying an application via a Group Policy? Make sure it’s either an MSI file, or contains a ZAP file for Group Policy.
How do you configure mandatory profiles? Rename ntuser.dat to ntuser.man
I can’t get multiple displays to work in Windows 2000. Multiple displays have to use peripheral connection interface (PCI) or Accelerated Graphics Port (AGP) port devices to work properly with Windows 2000.
What’s a maximum number of processors Win2k supports? 2
I had some NTFS volumes under my Windows NT installation. What happened to NTFS after Win 2k installation? It got upgraded to NTFS 5.
How do you convert a drive from FAT/FAT32 to NTFS from the command line? convert c: /fs:ntfs
Explain APIPA. Auto Private IP Addressing (APIPA) takes effect on Windows 2000 Professional computers if no DHCP server can be contacted. APIPA assigns the computer an IP address within the range of 169.254.0.0 through 169.254.255.254 with a subnet mask of 255.255.0.0.
How does Internet Connection Sharing work on Windows 2000? Internet Connection Sharing (ICS) uses the DHCP Allocator service to assign dynamic IP addresses to clients on the LAN within the range of 192.168.0.2 through 192.168.0.254. In addition, the DNS Proxy service becomes enabled when you implement ICS.
Tell the differences between Windows 95 and Windows NT? Lack of Unicode implementation for most of the functions of Win95. Different extended error codes. Different number window and menu handles. Windows 95 implements some window management features in 16 bits. Windows 95 uses 16-bit world coordinate system and the coordinates restricted to 32K. Deletion of drawing objects is different. Windows 95 does not implement print monitor DLLs of Windows NT. Differences in registry. Windows 95 does not support multiprocessor computers. NT implementation of scheduler is quite different. Different driver models. Win95 was built with back-compatibility in mind and ill-behaving 16-bit process may easily corrupt the system. Win95 starts from real DOS, while WinNT uses DOS emulation when one needs a DOS. Win95’s FAT is built over 16-bit win3.1 FAT (not FAT32!, actually, Win95’s FAT contains two FATs).
What is the effective way of DIB files management? A: Memory-mapped file is the best choice for device-independent bitmaps. MMF allows to map the file to RAM/SWAP addresses and to let Windows handle all load/unload operations for the file.
What should you be aware of if you design a program that runs days/weeks/months/years? A: When your program should run for a long time, you should be careful about heap allocations, because if you use new/delete intensively in your application, the memory becomes highly fragmented with a time. It is better to allocate all necessary memory in this case that many times small blocks. You should be especially careful about CString class which allocates permanent DLL
What are the advantages of using DLL’s? DLLs are run-time modular. DLL is loaded when the program needs it. Used as a code sharing between executables.
What are the different types of DLL’s? A: Extension, Regular and pure Win32 DLL (without MFC)
What are the differences between a User DLL and an MFC Extension DLL? A: Extension DLL supports a C++ interface, i.e. can export whole C++ classes and the client may construct objects from them. Extension DLL dynamically links to MFC DLLs (those which name starts with MFC??.DLL) and to be synchronous with the version it was developed for. Extension DLL is usually small (simple extension DLL might be around 10K) Regular DLL can be loaded by any Win32 environment (e.g. VB 5) Big restriction is that regular DLL may export only C-style functions. Regular DLLs are generally larger. When you build a regular DLL, you may choose a static link (in this case MFC library code is copied to your DLL) and dynamic (in this case you would need MFC DLLs to be presented on the target machine)
What do you have to do when you inherit from two CObject-based classes? A: First of all, this is a bad idea does not matter what tells you interviewer. Secondly, if you forced to use condemned rhombus structure, read Technical Note 16 in MSDN, which discusses why MFC does not support multiple inheritance and what to do in case you still need it (there are a few problems with CObject class, such as incorrect information, returned by IsKindOf() of CObject for MI, etc.)
What are the additional requirements for inheritance from CWnd-based classes? A: Again, this is the bad idea. Try to find alternative solution. Anyway, if you have to multiply inherit from CWnd-based class, the following are additional requirements to the above conditions (again, this is extremely bad question for interview!!!): There must be only one CWnd-derived base class. The CWnd-derived base class must be the first (or left-most) base class.
What is a “mutex”? A: Mutexes are the mechanism of process synchronization that might be used to synchronize data across multiple processes. Mutex is a waitable object while a critical section is not. Mutexes are significantly slower than critical sections.
What’s the difference between a “mutex” and a “critical section”? Critical section provides synchronization means for one process only, while mutexes allow data synchronization across processes.
What might be wrong with the following pseudo-code: FUNCTION F BEGIN INT I=2 DO I = I + 1 IF I = 4 THEN BREAK END DO END
A:This code is not thread safe. Suppose one thread increments I to 3 and then returns to the beginning of DO statement. Then it increments I to 4 and now context switch happens. Second thread increments I to 5. From this moment the code shown will execute forever until some external force intervention. Solution is obviously using some synchronization object to protect I from being changed by more than one thread.
What is a deadlock ? A: A deadlock, very simply, is a condition in which two or more threads wait for each other to release a shared resource before resuming their execution. Because all threads participating in a deadlock are suspended and cannot, therefore, release the resources they own, no thread can continue, and the entire application (or, worse, more than one application if the resources are shared between threads in multiple applications) appears to hang.
How can we create thread in MFC framework? A: Using AfxBeginThread.
What types of threads are supported by MFC framework? A: Working thread and windows thread. Working thread usually does not have a user interface and easier to use. Windows thread has an user interface and usually used to improve responsiveness of the user input. Message Map
When ON_UPDATE_COMMAND_UI is called? (message may vary) A: When a user of your application pulls down a menu, each menu item needs to know whether it should be displayed as enabled or disabled. The target of a menu command provides this information by implementing an ON_UPDATE_COMMAND_UI handler.
What is a “hook”? A: A point in the Windows message-handling mechanism where an application can install a subroutine to monitor messages. You need hooks to implement your own Windows message filter.
What are the difference between MFC Exception macros and C++ exception keywords? A:Actually, MFC macros may accept exception of only CException class or class, derived from CException, where as C++ exception mechanism accepts exception of ANY type Reusable Control Class
How would you set the background of an edit control to a customized color? A: You have several choices, but the simplest one is subclassing. Kruglinski in his “Inside Visual C++” describes pretty well this process. Generally, you derive the class from none control class, override the messages you want (like WM_CTLCOLOR) and then in init function like OnInitialUpdate of CDialog, subclass the control with SubclassDlgItem().
What is Message Reflection? How could you accomplish the above task using message reflection? A: See Technical Note 62 of MSDN. Usually, message is handled in the parent class that means you have to override message handler for each parent. Sometimes it is nice to handle a message in the control itself, without parent invocation. Such handling mechanism is called message reflection. Control “reflects” message to itself and then processes it. Use ON_<MESSAGE_NAME>_REFLECT macro to create a reflected message.
What is the command routing in MFC framework? A: CView => CDocument => CFrameWnd => CWinApp
What’s the purpose of CView class? CDocument class? What are relationships between them? A: The CView class provides the basic functionality for user-defined view classes. A view is attached to a document and acts as an intermediary between the document and the user: the view renders an image of the document on the screen or printer and interprets user input as operations upon the document. The CDocument class provides the basic functionality for user-defined document classes. A document represents the unit of data that the user typically opens with the File Open command and saves with the File Save command. Users interact with a document through the CView object(s) associated with it. A view is a child of a frame window. The relationship between a view class, a frame window class, and a document class is established by a CDocTemplate object. A view can be attached to only one document, but a document can have multiple views attached to it at once.
What class is responsible for document template in MDI application? A: CMultiDocTemplate.
What function must be used to add document template? A: AddDocTemplate.
What the main objects are created for SDI and MDI applications? A: CWinApp - application object. For MDI application with New document implementation CDocTemplate, CDocument, CView, CMainFrame. If your application is SDI, your CMainFrame class is derived from class CFrameWnd. If your application is MDI, CMainFrame is derived from class CMDIFrameWnd. For MDI application CMDIChildWindow is also created.
We have a loop for 800,000. It fails on 756,322. How can we get the information before it fails? A: You could think of several way to debug this: Set the condition in debugger to stop when loop is passed around 756321 times. Throw an exception within a loop (may be not the best idea since exception doe
Windows XP only