PORT NUMBERS
15 è Netstat
21 è FTP
23 è Telnet
25 è SMTP
37 @ TIME
42 è WINS
53 è DNS
67 è Bootp
68 è DHCP
79 @ FINGER
80 è HTTP
88 è Kerberos
101 è HOSTNAME
115 @ SFTP
110 è POP3
119 è NNTP
123 è NTP
(Network time protocol)
139 è NetBIOS
161 è SNMP
180 è RIS
220 @ IMAP3
389 è LDAP (Lightweight Directory Access
Protocol)
443 è HTTPS (HTTP over SSL/TLS)
443 è SSL (https) (http protocol over TLS/SSL
500 @ INTERNET KEY EXCHANGE
520 è RIP
3269 @ AD GLOBAL CATALOG
3389 è Terminal services
9100 @ GOOGLE
1) Components of computer?
Ans:
Two types of components. Processing devices are the
components responsible for the
processing of information within the computer
system. These include devices such as
the CPU, memory and motherboard. Storage
devices are components which
allow data to be stored within a computer
system such as hard disks.
2) What is SMPS?
Ans:
Switch-mode power supply.
3) What is BIOS?
Ans:
Basic input/output system. It is the program a
computer's microprocessor uses to get the computer system started after it is
turned on. It also manages data flow
between the computer's operating system and attached devices such as the hard
disk, video adapter, keyboard, mouse and printer.
4) What is POST?
Ans: Power-on self-test. A power-on self-test (POST) is a process
performed by firmware or software routines immediately after a computer or
other digital electronic device is powered on.
5) What is the boot process of XP?
Ans:
6) What is DHCP? Port number?
Ans:
Dynamic Host Configuration Protocol. It automatically assigns
IP to the system in the network , it has a process called DORA , D- Discover
,O-Offer , R- Request , A-
Acknowledge. Port number 67 for
Server and 68 for Client.
7) What is DNS? Port Number?
Ans:
Domain naming system
it resolves IP to Host name and host name to IP address. Port number is 53.
8) What is AD?
Ans:
Active directory. Active Directory is a database that keeps
track of all the user accounts and passwords in an organization. It allows to
store user accounts and passwords in one protected location, improving
organization's security. Active
Directory is subdivided into one or more domains.
9) What is SMTP? Port number?
Ans:
Simple Mail Transfer Protocol. It helps in sending mails. Port number is 25.
10)
What is
POP3?
Ans:
Post Office Protocol version 3. It is a standard mail protocol used to receive
emails from a remote server to a local email client. POP3 allows you to download email messages on
your local computer and read them even when you are offline.
11)
What is IP
Address?
Ans:
Internet Protocol. This is used to communicate to other systems over the
network.
12)
What is
Subnet mask?
Ans:
It is called
a subnet mask because it is used to
identify network address of an IP address by performing a bitwise AND
operation on the netmask. A Subnet mask is a 32-bit number
that masks an IP address, and divides the IP address
into network address and host address.
13)
How many
classes of IP addresses are there and the ranges?
Ans:
There are 5 types of
classes , Class A – 0 to 126, Class B – 128 to 191 , Class C 192 to 223, Class
D – 224 to 239, Class E – 240 to 254.
14)
What is
Hub, Switch and Router?
Ans:
15)
What is OSI
layer?
Ans:
The Open Systems Interconnection
is a conceptual model that characterizes and standardizes the internal
functions of a communication system by partitioning it into abstraction
layers. The model groups communication
functions into 7 logical layers. 1:
physical layer; 2: data link layer; 3: network layer; 4: transport layer; 5:
session layer; 6: presentation layer; 7: application layer.
16)
What is
Static IP and Dynamic IP?
Ans:
Static IP addresses are reserved IP addresses and do not change over
time while dynamic IP addresses can change each time when connecting to the
Internet.
17)
How will
you know if the IP assigned is Static or Dynamic?
Ans:
The simple way is to check the IP address each time we connect to
internet or we can use ipconfig/all in the command prompt or we can check the
status option of the internet connection in the control panel.
18)
How will
you enable remote desktop on the computer?
Ans:
Click start button, right click computer, click properties and select
"allow Remote Assistance to this computer."
19)
Difference
between Remote Desktop and Remote assistance?
Ans:
Remote Desktop is to access one computer from another remotely. Remote Assistance is to give or receive
assistance remotely.
20)
How will
you join system to domain?
Ans:
To connect a system to a domain, you'll need to know the name of the domain
and have a valid user account on the domain.
Click start, click computer and properties. Under 'computer name' tab, click
'change.' Under 'member of,' select
domain and give the name of the domain.
Type in the username and password given to connect to the domain.
21)
What will
you do when a system is affected from Virus?
Ans:
Check whether an antivirus program is installed, and if yes, update it
and scan the entire system. If there is
no antivirus installed, scan the system with an online antivirus program, scan
the system thoroughly and disinfect the virus.
22)
What is
SCCM?
Ans:
System Center Configuration Manager.
SCCM is a software management suite provided by Microsoft that allows
users to manage a large number of Windows based computers. SCCM features remote control, patch
management, operating system deployment, network protection and other various
services.
23)
What is
SCOM?
Ans:
System Center Operations Manager.
SCOM is a data center management system designed for Windows Server and Unix-based
operating systems. SCOM provides a user
interface for viewing a system's functionality, state and performance. Alerts can also be configured for
availability, configuration, performance and security events.
24)
What is
blue dump error and how will you fix it?
Ans: System crashes usually because of bad memory
module (RAM Configuration), failing hard drive, virus/Trojan attack etc., and
there is no single fix for that. To Fix
Blue Screen Memory Dump Error, try the following: 1. Repair/Clean Registry. 2. Scan for Virus. 3. Check the recently installed hardware and
device driver. 4. Check for a faulty RAM
or ports.
25)
What will u
do when u see NTLDR missing?
Ans:
Disconnect any non-bootable external devices, check the BIOS settings
and ensure they are correct, restore ntdlr and ntdetect.com, perform repair
installation or perform a clean installation.
26)
Difference
between FAT32 and NTFS?
Ans:
FAT32 (File Allocation Table 32-bit) file systems used in Windows ME and
lower. NTFS (New Technology File System)
is used in Windows 2000 and newer. FAT32
only supports files no larger than 3.9 GB and NTFS supports files larger than 4
GB in size. NTFS is more secure and
advanced compared to FAT32.
1.Difference between Switch and Hub
Switch HUB
a. Works at layer 2 works at layer 1
b. Uses MAC address for packet uses broadcast for packet forwarding
forwarding
c. Does not required CSMA/CD requires CSMA/CD
d. Faster than HUB Slower than Switch
e. Full-duplex Half-duplex
f. high throughput Low throughput
2.What is bandwidth of of CAT5 & CAT 6 cables?
Answer: CAT 5 - 100 Mbps, CAT 6 – 1000 Mbps
3. What is the recommended CAT5 cable length between switch and PC ?
Answer: 100 meters
4. When to use cross cable and straight cable?
Answer: Similar device = cross cable
• Switch to switch
• PC to PC
• Hub to HUB
• Switch to HUB
• PC to router
• router to router
Unsimilar device = straight cable
• PC to switch
• PC to HUB
• Router to Switch
5. Difference between domain and work group?
Answer:
Domain Workgroup
A. centralized network model Decentralized network
B. Domain is controlled by DC No centralized control
C. Centralized login Local login
D. centralized user database local user data based
E. Easy and centralized management NA
F. good for large network good for small network
6. Explain in short about all 7 layers of OSI
Answer:
• Application layer - user interface and application Data conversion
• Presentation layer - and transformation keep data of diff
• Session layer - application separately end to end connectivity
• Transport layer - using port numbers, logical addressing like IP
• Network layer - address. Physical addressing like MAC
• Data link layer - address. Physical transmission of data using
• Physical layer - O's and l's.
7. What if forest. ?
Answer: forest is collection of single or multiple trees.
8. What is trees?
Answer: Trees are collection of single or multiple domain arrange in hierarchy using child-parent relationship.
9. Which authentication protocols are supported by ADS?
Answer: NTLM and Kerberos
10. What is Global Catalog?
Answer: GC is a DC which maintains full copy of local domain parti on and partial copy of entire forest.
11.Define Active directory service?
Answer: ADS is a new logical network model of windows 2000 and 2003 which includes forest, trees, domain, etc.
12.What is function of LDAP?
Answer: LDAP is a protocol used to query or access active directory database. It uses port 389.
13. What are the requirements for ADS?
Answer:
A) Windows 2000/2003 Server Operating System
b) TCP/IP protocol and IP address
c) Network Card with Active state
d) NTFS partition
14. What is Sysvol?
Answer: Sysvol (System Volume) a special folder located on NTFS partition of DC for storing domain public files like logon script, GPO templates, etc. The contents of sysvol folder are replicated to all DC in a domain.
15. Difference between FAT32 and NTFS?
Answer:
FAT32 NTFS
a. Supported by win9x, 2000, 2003, xp Supported by NT, 2000, 2003, xp
b. Remote security Local security
c. NA compression and encryption
d. NA Hot Fixing
e. NA Shadow copy and Disk quota
16. Difference between Basic disk and dynamic disk?
Answer:
Basic Disk Dynamic disk
partition are created Volumes are created
can be converted to dynamic cannot be converted to basic
grouping of disk not allowed grouping of disk are allowed
No data redundancy data redundancy using RAID 1/5
partition table is at start Partition table is at end
17. Explain about RAID-1
Answer:
A. Min. and max. 2 hard disk
b. If any one disk fails data can be recovered from other disk.
c. 50% space wastage.
D. no read/write performance improvement.
E. good for storing Operating system.
18. Explain about RAID-5
Answer:
A. data is stored in distributed format across all the disk
B. min 3 max. 32
C. if any one disk fails data can be recovered using parity.
D. parity space wastage eg. parity = total space \ no of disk.
E. good for storing data.
19. Can we convert FAT32 to NTFS? How?
Answer: you can convert FAT32 partition to NTFS using convert.exe command.
Eg . convert /fs:ntfs
20. What is mounting?
Answer: mounting is a process of assigning or mapping of the folder to a drive.
21. What is RAID?
Answer: RAID is a technology of grouping disk in order to provide more space and redundancy. There are total 54 RAID method. Windows 2003 support RAID 0, 1 and 5.
22. What is difference between mirroring and duplexing?
Answer: Mirroring requires single controller and duplexing requires two controllers.
23. What is Web Server?
Answer: Web server is a server or application server which host or stores websites. Every web site should have a name like www.vision.com and IP address. Eg. IIS, Apache server, etc.
34. What is mail server?
Answer: Mail server is a software which maintains user mailboxes, eg : Exchange server , Lotus domino, etc.
35. What is mail client?
Answer: software used by client to access to mails stores on mail server, using mail client software you can send mail and receive mail. Eg: Microsoft Outlook, Outlook Express, Lotus notes, etc.
36. What is Proxy server?
Answer: It is software used for sharing of internet connection.
E.g. Wingate, Win proxy, Analog proxy, etc.
37. Port numbers for various application and services?
Answer:
There are total 65536 ports available. Below are the lists of some well-known ports.
LDAP : 389
Global catalog:
Kerberos : 88
DNS : 53
SMTP : 25
POP3 : 110
Telnet : 23
NNTP : 119
IMAP : 143
RPC : 135
HTTP : 80
HTTPS/SSL : 443
FTP : 21
38. What is firewall?
Answer: It is software used to provide security to your network by not allowing unauthorized access to your internal network from External users. Eg: PIX firewall, Checkpoint firewall, etc.
1) What is Active Directory?
A central component of the Windows platform, Active Directory directory service provides the means to manage the identities and relationships that make up network environments. For example we can create, manage and administor users, computers and printers in the network from active directory.
2) What is DNS? Why it is used? What is "forward lookup" and "reverse lookup" in DNS? What are A records and mx records?
DNS is domain naming service and is used for resolving names to IP address and IP addresses to names. The computer understands only numbers while we can easily remember names. So to make it easier for us what we do is we assign names to computers and websites. When we use these names (Like yahoo.com) the computer uses DNS to convert to IP address (number) and it executes our request.
Forward lookup: Converting names to IP address is called forward lookup.
Reverse lookup: Resolving IP address to names is called reverse lookup.
'A' record: Its called host record and it has the mapping of a name to IP address. This is the record in DNS with the help of which DNS can find out the IP address of a name.
'MX' Record: its called mail exchanger record. Its the record needed to locate the mail servers in the network. This record is also found in DNS.
3) What id DHCP? Why it is used? What are scopes and super scopes?
DHCP: Dynamic host configuration protocol. Its used to allocate IP addresses to large number of PCs in a network environment. This makes the IP management very easy.
Scope: Scope contains IP address like subnet mask, gateway IP, DNS server IP and exclusion range which a client can use to communicate with the other PCs in the network.
Superscope: When we combine two or more scopes together its called super scope.
4) What are the types of LAN cables used? What is a cross cable?
Types of LAN cables that are in use are "Cat 5" and "Cat 6". "Cat 5" can support 100 Mbps of speed and "CAT 6" can support 1Gbps of speed.Cross cable: Its used to connect same type of devices without using a switch/hub so that they can communicate.
5) What is the difference between a normal LAN cable and cross cable? What could be the maximum length of the LAN cable?
The way the paired wires are connected to the connector (RJ45) is different in cross cable and normal LAN cable. The theoritical length is 100 meters but after 80 meters you may see drop in speed.
6) What would you use to connect two computers without using switches?
Cross cable.
7) What is IPCONFIG command? Why it is used?
IPCONFIG command is used to display the IP information assigned to a computer. Fromthe output we can find out the IP address, DNS IP address, gateway IP address assigned to that computer.
8) What is APIPA IP address? Or what IP address is assigned to the computer when the DHCP server is not available?
When DHCP server is not available the Windows client computer assignes an automatic IP address to itself so that it can communicate with the network cmputers. This ip address is called APIPA. ITs in the range of 169.254.X.X. APIPA stands for Automatic private IP addressing.
9) What is a DOMAIN? What is the difference between a domain and a workgroup?
Domain is created when we install Active Directory. ITs a security boundary which is used to manage computers inside the boundary.
Domain can be used to centrally administor computers and we can govern them using commo policies called group policies. We can't do the same with workgroup.
10) Do you know how to configure outlook 2000 and outlook 2003 for a user?
Please visit the link below to find out how to configure outlook 2000 and outlook 2003.http://www.it.cmich.edu/quickguides/qg_outlook2003_server.asp
11) What is a PST file and what is the difference between a PST file and OST file? What file is used by outlook express?
PST file is used to store the mails locally when using outlook 2000 or 2003. OST file is used when we use outlook in cached exchanged mode. Outlook express useds odb file.
12) What is BSOD? What do you do when you get blue screen in a computer? How do you troubleshoot it?
BSOD stands for blue screen of Death. when there is a hardware or OS fault due to which the windows OS can run it give a blue screen with a code. Best way to resolve it is to boot the computer is "LAst known good configuration". If this doesn't work than boot the computer in safe mode. If it boots up than the problemis with one of the devices or drivers.
13) What is RIS? What is Imaging/ghosting?
RIS stands for remote installation services. You save the installed image on a windows server and then we use RIS to install the configured on in the new hardware. We can use it to deploy both server and client OS.
Imaging or ghosting also does the same job of capturing an installed image and then install it on a new hardware when there is a need. We go for RIS or iamging/ghosting because installing OS everytime using a CD can be a very time consuming task. So to save that time we can go for RIS/Ghosting/imaging.
14) What is VPN and how to configure it?
VPN stands for Virtual private network. VPN is used to connect to the corporate network to access the resources like mail and files in the LAN. VPN can be configured using the stepsmentioned in the KB:http://support.microsoft.com/kb/305550
15) Your computer slowly drops out of network. A reboot of the computer fixes the problem. What to do to resolve this issue?
Update the network card driver.
16) Your system is infected with Virus? How to recover the data?
Install another system. Install the OS with the latets patches, Antivirus with latest updates. Connect the infected HDD as secondary drive in the system. Once done scan and clean the secondary HDD. Once done copy the files to the new system.
17) How to join a system to the domain? What type of user can add a system to the domain?
Please visit the article below and read "Adding the Workstation to the Domain
18) What is the difference between a switch and a hub?
Switch sends the traffic to the port to which its meant for. Hub sends the traffic to all the ports.
19) What is a router? Why we use it?
Router is a switch which uses routing protocols to process and send the traffic. It also receives the traffic and sends it across but it uses the routing protocols to do so.
20) What are manageable and non manageable switches?
Switches which can be administered are called manageable switches. For example we can create VLAN for on such switch. On no manageable switches we can't do so.
IT Helpdesk Questions
Technical Questions
1. What is NIC?
A network card, network adapter or NIC (network interface controller) is a piece of computer hardware designed to allow computers to communicate over a computer network
2. What is USB?
Universal Serial Bus (USB) is a serial bus standard to interface devices. Devices like Modem, Mouse, Keyboard etc can be connected.
3. Dialup vs. Broadband
A broadband connection (ADSL) provides high-speed Internet access over a standard phone line. The advantage of a broadband connection over a standard dialup service, is that Broadband is considerably faster, and is "always-on", meaning that once you"re logged on, your PC is online until the PC is turned off again.
Broadband offer high-speed Internet access and allows telephone calls and a permanent Internet connection to share a single phone line simultaneously whereas in Dialup connection either Internet connection or telephone call can made at given time.
4. LAN and WAN
A local area network is a computer network covering a small geographic area, like a home, office, or group of buildings
Wide Area Network (WAN) is a computer network that covers a broad area (i.e., any network whose communications links cross metropolitan, regional, or national boundaries). Or, less formally, a network that uses routers and public communications links
5. Microsoft Access
Microsoft Office Access, previously known as Microsoft Access, is a relational database management system from Microsoft.
6. What is RAS?
Remote Access Services (RAS) refers to any combination of hardware and software to enable the remote access to tools or information that typically reside on a network of IT devices.
7. Difference between Client Mail and Web Mail?
Email clients download your emails onto your computer. Using a specialized email program such as Outlook Express or Apple Mail has the advantage of giving you complete control over your email; every email you receive is placed on your computer and you can keep as many large file attachments as you want.
Checking your email through our webmail is similar to using Hotmail or Yahoo! Mail. You never actually copy your messages to your computer; in fact, you are looking at them through your web browser on somebody else"s computer. When you are not online, you are not able to see your email.
8. RAM and ROM
random access memory, a type of computer memory that can be accessed randomly; that is, any byte of memory can be accessed without touching the preceding bytes. RAM is the most common type of memory found in computers and other devices, such as printers.
Pronounced rahm, acronym for read-only memory, computer memory on which data has been prerecorded. Once data has been written onto a ROM chip, it cannot be removed and can only be read. Unlike main memory (RAM), ROM retains its contents even when the computer is turned off. ROM is referred to as being nonvolatile, whereas RAM is volatile.
9. Spamguard
Spam Guard is an Outlook add-in that filters email that arrives in your inbox. If the sender of any message cannot be identified then the message is moved into a spam quarantine folder. Messages deposited in the spam quarantine folder can be inspected and either deleted or approved at your leisure.
10. Firewall and Antivirus
A system designed to prevent unauthorized access to or from a private network. Firewalls can be implemented in both hardware and software, or a combination of both. Firewalls are frequently used to prevent unauthorized Internet users from accessing private networks connected to the Internet, especially intranets. All messages entering or leaving the intranet pass through the firewall, which examines each message and blocks those that do not meet the specified security criteria.
Antivirus is a software program which helps protect a computer against being infected by a virus.
11. 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.
12. IPConfig
IPConfig is a command line tool used to control the network connections on Windows NT/2000/XP machines. There are three main commands: "all", "release", and "renew". IPConfig displays all current TCP/IP network configuration values and refreshes Dynamic Host Configuration Protocol (DHCP) and Domain Name System (DNS) settings. Used without parameters, IPConfig displays the IP address, subnet mask, and default gateway for all adapters.
13. Trace route
Trace route is the program that shows you the route over the network between two systems, listing all the intermediate routers a connection must pass through to get to its destination. It can help you determine why your connections to a given server might be poor, and can often help you figure out where exactly the problem is. It also shows you how systems are connected to each other, letting you see how your ISP connects to the Internet as well as how the target system is connected.
DNS:A Domain Naming server is a hierarchical namespace structure designed to provide host to IP address name resolution and registration.
DNS ZONE TYPE:
Forward lookup zone: resolves names to IP address.
Reverse lookup zone:
resolves IP addresses to Host names.
AD INTEGRATED ZONE
AD–integrated DNS enables AD storage and replication of DNS zone databases. Windows 2000 & 2003 DNS servers which accommodates storing zone data in AD. When you configure a computer as a DNS server, zones are usually stored as text files on name servers — that is, all of the zones required by DNS are stored in a text file on the server computer. These text files must be synchronized among DNS name servers by using a system that requires a separate replication topology and schedule called a zone transfer However, if you use AD integrated DNS you configure a domain controller as a DNS name server, zone data is stored as an AD object and is replicated as part of domain replication.
STUB ZONE
A Stub zone is a read only copy of a zone that contains only those resources records necessary to identify the authoritative DNS servers for the actual zone. A stub zone is used to keep a parent zone aware of authoritative DNS servers for a delegated zone and thereby maintain DNS name resolution efficiently. A stub zone is conposed of (A), (NS), (SOA)
Types of DNS Records: -
A(Host):
Represents a computer or device on the network. 'A'records are the most common and most used DNS records.
PTR(Pointer):
Used for finding the DNS name that corresponds to an IP address. The PTR is found only in the reverse lookup zone.
NS(NameServer):
The NS RRs facilitate delegation by identifying DNS servers for each zone. They appear in all forward and reverse look-up zones.
SOA(Start Of Authority):
The first record in any zone file is a SOA. the SOA identifies a primary DNS name server for the zone as the best source of information for the data within that zone and as an entity processing the updates for the zone.
SRV(Service Record):
Indicates a network service offered by a host.- CNAME(Alias):an alias is hostname that refers to another hostname.
=========================================
DHCP: Is a standard for simplifing management of host IP configuration.
SUPERSCOPE: Superscope is a administrative feature of DHCP server that you can create and manage through the DHCP console. Using a Superscope you can group multiple scopes as a single administrative entity.
DHCP Authorize: This procedure is usually only needed if you are running a DHCP server on a member server. In most cases, if you are installing a DHCP server on a computer also running as a domain controller, the server is automatically authorized the first time you add the server to the DHCP console.
SCOPE: DHCP scope is a poole of IP addresses which are offered to DHCP clients.
=========================================
WHAT ARE FSMO ROLES IN ACTIVE DIRECTORY?
Windows 2000 and Windows 2003 Active directory follow the multimaster model. Under this model there are five roles which which can be held by the DCs (Domian Controllers).
The five roles are given below:
• Schema Master: The schema master domain controller controls all updates and modifications to the schema. To update the schema of a forest, you must have access to the schema master. There can be only one schema master in the whole forest.
• Domain naming master: The domain naming master domain controller controls the addition or removal of domains in the forest. There can be only one domain naming master in the whole forest.
• Infrastructure Master: The infrastructure is responsible for updating references from objects in its domain to objects in other domains. At any one time, there can be only one domain controller acting as the infrastructure master in each domain.
• Relative ID (RID) Master: The RID master is responsible for processing RID pool requests from all domain controllers in a particular domain. At any one time, there can be only one domain controller acting as the RID master in the domain.
• PDC Emulator: The PDC emulator is a domain controller that advertises itself as the primary domain controller (PDC) to workstations, member servers, and domain controllers that are running earlier versions of Windows. For example, if the domain contains computers that are not running Microsoft Windows XP Professional or Microsoft Windows 2000 client software, or if it contains Microsoft Windows NT backup domain controllers, the PDC emulator master acts as a Windows NT PDC. It is also the Domain Master Browser, and it handles password discrepancies. At any one time, there can be only one domain controller acting as the PDC emulator master in each domain in the forest.
What is replication in active directory?
REPLICATION Replication is a process of sending update information for data that has changed in the directory to other domain controllers, as a Part of the AD planning an implementation process.*2000/2003 uses MULTI-MASTER replication for the AD.
Types of UPDATES which force replication: Add, Modify, ModifyDN, delete
USN: Update sequence numbers
GUID: Globally unique identifier
REPLICATION PARTITIONS:
Schema Partition: contains object and attribute definitions. In other words it contains a list of definitions that define what objects and attributes for those objects can exist in the AD.
Configuration partition: contains information about the physical structure of the AD, such as the sites and domains and where DC resides in the enterprise. It is replicated to all DC's in the tree or forest.
Domain partition: contains information about all AD objects that are specific to that domain, such as users, groups and other resources. All domain partition information is completely replicated to all domain controllers within the domain.
REPLICATION TOPOLOGY
KCC: Knowledge Consistency Checker: It builds the topology for the intrasite replication between the DCs. It uses only RPC to communicate with the directory service.
Bridgehead server: A point where a replication information leaves or enters a site for intersite replication.
BENIFITS
• Optimize replication for speed and bandwidth consumption between domain controllers.• Locate the closest domain controller for client logon, services, and directory searches.
• Direct a Distributed File System (DFS) client to the server that is hosting the requested data within the site.
• Replicate the system volume (SYSVOL), a collection of folders in the file system that exists on each domain controller in a domain and is required for implementation of Group Policy
=============================================================
What is RAID?
ANS: Redundant Array of Inexpensive disk is a way to increase capaxity, performance and reliablility.
RAID0: (Striping) Not really RAID as it has no fault tolerance, Data is striped across all disks, Excelent read/write performance.
RAID1: (Mirroring) Need at least 2 drives, tolerates single drive failure, often used for OS drive or boot volume.
RAID5: Requires at least 3 drives, data and parity striped across all disks, can tolerate failure of any one disk without losing data but performance does degrade.
TCP/IP MODEL:
Application Layer
Transport Layer
Internet
Network Interface
OSI MODEL
Application Layer
Presentation layer
Session layer
Transport Layer
Network Layer
Data-link Layer
Physical layer
What is a switch?
A network switch, or bridge, is a specialized device that connects multiple network segments. It's a more modern and efficient form of the ubiquitous (and outdated) network hub. A hub, also known as a repeater, is a simple device that has been used for years to connect all nodes, or computers, on a network to a central location. Each node on a network has a unique hardware address called a MAC address. A hub is known as a repeater because when a packet of data, or frame, is sent through the hub, it is repeated to each and every computer on the network.This means that if a 1 GB video is sent to one computer through the hub, the file will also be sent to all of the other computers on the hub. This is very inefficient for bandwidth management. "Hubs have two major drawbacks," says Ben deGonzague, a deployment engineer with TopCoder Software, a Glastonbury, Conn.-based software engineering firm. "First, network bandwidth is consumed as each and every frame is sent to all devices on a network. Second, your network is only as fast as the slowest device. Hubs have become obsolete with switching-based networks."A switch-based network is one that utilizes switches instead of hubs. A switch is a major upgrade to a hub. Instead of sending all network data to each and every network node, the switch will analyze the MAC address and determine where to send the data. Network bandwidth is not wasted by sending every frame to every port.So when a switch receives data for a file, if it was addressed to one computer it will only be sent there. The other computers on the network wouldn't know about it. This means that the network is now much more efficient, but it's also a step toward being more secure: "Since switches can segregate traffic from different nodes," says deGonzague, "this makes it more difficult for anyone to capture packets on your network.
What is a router?
While switches connect multiple computers, a router is required to connect multiple networks, like your LAN to the Internet. Routers work by storing large tables of networks and addresses, then using algorithms to determine the shortest routes to individual addresses within those networks. In this way efficient routers not only facilitate intra-network communications, but also play a role in overall network performance. delivering the information faster.While many consumers are familiar with small routers from companies like Linksys, which can be purchased for less than $50 at computer hardware stores, they shouldn't be confused with a proper router for business. "A typical router at home will connect your cable modem or DSL network to your internal network. This is just connecting two different networks. Routers for businesses on the other hand might have to connect several different networks," says deGonzague. Small business routers from vendors like Cisco often include management software, enabling IT staff to better manage network stability and, ultimately, performance.
1) What is Active Directory?
A central component of the Windows platform, Active Directory directory service provides the means to manage the identities and relationships that make up network environments. For example we can create, manage and administor users, computers and printers in the network from active directory.
2) What is DNS? Why it is used? What is "forward lookup" and "reverse lookup" in DNS? What are A records and mx records?
DNS is domain naming service and is used for resolving names to IP address and IP addresses to names. The computer understands only numbers while we can easily remember names. So to make it easier for us what we do is we assign names to computers and websites. When we use these names (Like yahoo.com) the computer uses DNS to convert to IP address (number) and it executes our request.
Forward lookup: Converting names to IP address is called forward lookup.
Reverse lookup: Resolving IP address to names is called reverse lookup.
'A' record: Its called host record and it has the mapping of a name to IP address. This is the record in DNS with the help of which DNS can find out the IP address of a name.
'MX' Record: its called mail exchanger record. Its the record needed to locate the mail servers in the network. This record is also found in DNS.
3) What id DHCP? Why it is used? What are scopes and super scopes?
DHCP: Dynamic host configuration protocol. Its used to allocate IP addresses to large number of PCs in a network environment. This makes the IP management very easy.
Scope: Scope contains IP address like subnet mask, gateway IP, DNS server IP and exclusion range which a client can use to communicate with the other PCs in the network.
Superscope: When we combine two or more scopes together its called super scope.
4) What are the types of LAN cables used? What is a cross cable?
Types of LAN cables that are in use are "Cat 5" and "Cat 6". "Cat 5" can support 100 Mbps of speed and "CAT 6" can support 1Gbps of speed.Cross cable: Its used to connect same type of devices without using a switch/hub so that they can communicate.
5) What is the difference between a normal LAN cable and cross cable? What could be the maximum length of the LAN cable?
The way the paired wires are connected to the connector (RJ45) is different in cross cable and normal LAN cable. The theoritical length is 100 meters but after 80 meters you may see drop in speed.
6) What would you use to connect two computers without using switches?
Cross cable.
7) What is IPCONFIG command? Why it is used?
IPCONFIG command is used to display the IP information assigned to a computer. Fromthe output we can find out the IP address, DNS IP address, gateway IP address assigned to that computer.
8) What is APIPA IP address? Or what IP address is assigned to the computer when the DHCP server is not available?
When DHCP server is not available the Windows client computer assignes an automatic IP address to itself so that it can communicate with the network cmputers. This ip address is called APIPA. ITs in the range of 169.254.X.X. APIPA stands for Automatic private IP addressing.
9) What is a DOMAIN? What is the difference between a domain and a workgroup?
Domain is created when we install Active Directory. ITs a security boundary which is used to manage computers inside the boundary.
Domain can be used to centrally administor computers and we can govern them using commo policies called group policies. We can't do the same with workgroup.
10) Do you know how to configure outlook 2000 and outlook 2003 for a user?
Please visit the link below to find out how to configure outlook 2000 and outlook 2003.http://www.it.cmich.edu/quickguides/qg_outlook2003_server.asp
11) What is a PST file and what is the difference between a PST file and OST file? What file is used by outlook express?
PST file is used to store the mails locally when using outlook 2000 or 2003. OST file is used when we use outlook in cached exchanged mode. Outlook express useds odb file.
12) What is BSOD? What do you do when you get blue screen in a computer? How do you troubleshoot it?
BSOD stands for blue screen of Death. when there is a hardware or OS fault due to which the windows OS can run it give a blue screen with a code. Best way to resolve it is to boot the computer is "LAst known good configuration". If this doesn't work than boot the computer in safe mode. If it boots up than the problemis with one of the devices or drivers.
13) What is RIS? What is Imaging/ghosting?
RIS stands for remote installation services. You save the installed image on a windows server and then we use RIS to install the configured on in the new hardware. We can use it to deploy both server and client OS.
Imaging or ghosting also does the same job of capturing an installed image and then install it on a new hardware when there is a need. We go for RIS or iamging/ghosting because installing OS everytime using a CD can be a very time consuming task. So to save that time we can go for RIS/Ghosting/imaging.
14) What is VPN and how to configure it?
VPN stands for Virtual private network. VPN is used to connect to the corporate network to access the resources like mail and files in the LAN. VPN can be configured using the stepsmentioned in the KB:http://support.microsoft.com/kb/305550
15) Your computer slowly drops out of network. A reboot of the computer fixes the problem. What to do to resolve this issue?
Update the network card driver.
16) Your system is infected with Virus? How to recover the data?
Install another system. Install the OS with the latets patches, Antivirus with latest updates. Connect the infected HDD as secondary drive in the system. Once done scan and clean the secondary HDD. Once done copy the files to the new system.
17) How to join a system to the domain? What type of user can add a system to the domain?
Please visit the article below and read "Adding the Workstation to the Domain
18) What is the difference between a switch and a hub?
Switch sends the traffic to the port to which its meant for. Hub sends the traffic to all the ports.
19) What is a router? Why we use it?
Router is a switch which uses routing protocols to process and send the traffic. It also receives the traffic and sends it across but it uses the routing protocols to do so.
20) What are manageable and non manageable switches?
Switches which can be administered are called manageable switches. For example we can create VLAN for on such switch. On no manageable switches we can't do so.
IT Helpdesk Questions
Technical Questions
1. What is NIC?
A network card, network adapter or NIC (network interface controller) is a piece of computer hardware designed to allow computers to communicate over a computer network
2. What is USB?
Universal Serial Bus (USB) is a serial bus standard to interface devices. Devices like Modem, Mouse, Keyboard etc can be connected.
3. Dialup vs. Broadband
A broadband connection (ADSL) provides high-speed Internet access over a standard phone line. The advantage of a broadband connection over a standard dialup service, is that Broadband is considerably faster, and is "always-on", meaning that once you"re logged on, your PC is online until the PC is turned off again.
Broadband offer high-speed Internet access and allows telephone calls and a permanent Internet connection to share a single phone line simultaneously whereas in Dialup connection either Internet connection or telephone call can made at given time.
4. LAN and WAN
A local area network is a computer network covering a small geographic area, like a home, office, or group of buildings
Wide Area Network (WAN) is a computer network that covers a broad area (i.e., any network whose communications links cross metropolitan, regional, or national boundaries). Or, less formally, a network that uses routers and public communications links
5. Microsoft Access
Microsoft Office Access, previously known as Microsoft Access, is a relational database management system from Microsoft.
6. What is RAS?
Remote Access Services (RAS) refers to any combination of hardware and software to enable the remote access to tools or information that typically reside on a network of IT devices.
7. Difference between Client Mail and Web Mail?
Email clients download your emails onto your computer. Using a specialized email program such as Outlook Express or Apple Mail has the advantage of giving you complete control over your email; every email you receive is placed on your computer and you can keep as many large file attachments as you want.
Checking your email through our webmail is similar to using Hotmail or Yahoo! Mail. You never actually copy your messages to your computer; in fact, you are looking at them through your web browser on somebody else"s computer. When you are not online, you are not able to see your email.
8. RAM and ROM
random access memory, a type of computer memory that can be accessed randomly; that is, any byte of memory can be accessed without touching the preceding bytes. RAM is the most common type of memory found in computers and other devices, such as printers.
Pronounced rahm, acronym for read-only memory, computer memory on which data has been prerecorded. Once data has been written onto a ROM chip, it cannot be removed and can only be read. Unlike main memory (RAM), ROM retains its contents even when the computer is turned off. ROM is referred to as being nonvolatile, whereas RAM is volatile.
9. Spamguard
Spam Guard is an Outlook add-in that filters email that arrives in your inbox. If the sender of any message cannot be identified then the message is moved into a spam quarantine folder. Messages deposited in the spam quarantine folder can be inspected and either deleted or approved at your leisure.
10. Firewall and Antivirus
A system designed to prevent unauthorized access to or from a private network. Firewalls can be implemented in both hardware and software, or a combination of both. Firewalls are frequently used to prevent unauthorized Internet users from accessing private networks connected to the Internet, especially intranets. All messages entering or leaving the intranet pass through the firewall, which examines each message and blocks those that do not meet the specified security criteria.
Antivirus is a software program which helps protect a computer against being infected by a virus.
11. 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.
12. IPConfig
IPConfig is a command line tool used to control the network connections on Windows NT/2000/XP machines. There are three main commands: "all", "release", and "renew". IPConfig displays all current TCP/IP network configuration values and refreshes Dynamic Host Configuration Protocol (DHCP) and Domain Name System (DNS) settings. Used without parameters, IPConfig displays the IP address, subnet mask, and default gateway for all adapters.
13. Trace route
Trace route is the program that shows you the route over the network between two systems, listing all the intermediate routers a connection must pass through to get to its destination. It can help you determine why your connections to a given server might be poor, and can often help you figure out where exactly the problem is. It also shows you how systems are connected to each other, letting you see how your ISP connects to the Internet as well as how the target system is connected.
DNS:A Domain Naming server is a hierarchical namespace structure designed to provide host to IP address name resolution and registration.
DNS ZONE TYPE:
Forward lookup zone: resolves names to IP address.
Reverse lookup zone:
resolves IP addresses to Host names.
AD INTEGRATED ZONE
AD–integrated DNS enables AD storage and replication of DNS zone databases. Windows 2000 & 2003 DNS servers which accommodates storing zone data in AD. When you configure a computer as a DNS server, zones are usually stored as text files on name servers — that is, all of the zones required by DNS are stored in a text file on the server computer. These text files must be synchronized among DNS name servers by using a system that requires a separate replication topology and schedule called a zone transfer However, if you use AD integrated DNS you configure a domain controller as a DNS name server, zone data is stored as an AD object and is replicated as part of domain replication.
STUB ZONE
A Stub zone is a read only copy of a zone that contains only those resources records necessary to identify the authoritative DNS servers for the actual zone. A stub zone is used to keep a parent zone aware of authoritative DNS servers for a delegated zone and thereby maintain DNS name resolution efficiently. A stub zone is conposed of (A), (NS), (SOA)
Types of DNS Records: -
A(Host):
Represents a computer or device on the network. 'A'records are the most common and most used DNS records.
PTR(Pointer):
Used for finding the DNS name that corresponds to an IP address. The PTR is found only in the reverse lookup zone.
NS(NameServer):
The NS RRs facilitate delegation by identifying DNS servers for each zone. They appear in all forward and reverse look-up zones.
SOA(Start Of Authority):
The first record in any zone file is a SOA. the SOA identifies a primary DNS name server for the zone as the best source of information for the data within that zone and as an entity processing the updates for the zone.
SRV(Service Record):
Indicates a network service offered by a host.- CNAME(Alias):an alias is hostname that refers to another hostname.
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DHCP: Is a standard for simplifing management of host IP configuration.
SUPERSCOPE: Superscope is a administrative feature of DHCP server that you can create and manage through the DHCP console. Using a Superscope you can group multiple scopes as a single administrative entity.
DHCP Authorize: This procedure is usually only needed if you are running a DHCP server on a member server. In most cases, if you are installing a DHCP server on a computer also running as a domain controller, the server is automatically authorized the first time you add the server to the DHCP console.
SCOPE: DHCP scope is a poole of IP addresses which are offered to DHCP clients.
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WHAT ARE FSMO ROLES IN ACTIVE DIRECTORY?
Windows 2000 and Windows 2003 Active directory follow the multimaster model. Under this model there are five roles which which can be held by the DCs (Domian Controllers).
The five roles are given below:
• Schema Master: The schema master domain controller controls all updates and modifications to the schema. To update the schema of a forest, you must have access to the schema master. There can be only one schema master in the whole forest.
• Domain naming master: The domain naming master domain controller controls the addition or removal of domains in the forest. There can be only one domain naming master in the whole forest.
• Infrastructure Master: The infrastructure is responsible for updating references from objects in its domain to objects in other domains. At any one time, there can be only one domain controller acting as the infrastructure master in each domain.
• Relative ID (RID) Master: The RID master is responsible for processing RID pool requests from all domain controllers in a particular domain. At any one time, there can be only one domain controller acting as the RID master in the domain.
• PDC Emulator: The PDC emulator is a domain controller that advertises itself as the primary domain controller (PDC) to workstations, member servers, and domain controllers that are running earlier versions of Windows. For example, if the domain contains computers that are not running Microsoft Windows XP Professional or Microsoft Windows 2000 client software, or if it contains Microsoft Windows NT backup domain controllers, the PDC emulator master acts as a Windows NT PDC. It is also the Domain Master Browser, and it handles password discrepancies. At any one time, there can be only one domain controller acting as the PDC emulator master in each domain in the forest.
What is replication in active directory?
REPLICATION Replication is a process of sending update information for data that has changed in the directory to other domain controllers, as a Part of the AD planning an implementation process.*2000/2003 uses MULTI-MASTER replication for the AD.
Types of UPDATES which force replication: Add, Modify, ModifyDN, delete
USN: Update sequence numbers
GUID: Globally unique identifier
REPLICATION PARTITIONS:
Schema Partition: contains object and attribute definitions. In other words it contains a list of definitions that define what objects and attributes for those objects can exist in the AD.
Configuration partition: contains information about the physical structure of the AD, such as the sites and domains and where DC resides in the enterprise. It is replicated to all DC's in the tree or forest.
Domain partition: contains information about all AD objects that are specific to that domain, such as users, groups and other resources. All domain partition information is completely replicated to all domain controllers within the domain.
REPLICATION TOPOLOGY
KCC: Knowledge Consistency Checker: It builds the topology for the intrasite replication between the DCs. It uses only RPC to communicate with the directory service.
Bridgehead server: A point where a replication information leaves or enters a site for intersite replication.
BENIFITS
• Optimize replication for speed and bandwidth consumption between domain controllers.• Locate the closest domain controller for client logon, services, and directory searches.
• Direct a Distributed File System (DFS) client to the server that is hosting the requested data within the site.
• Replicate the system volume (SYSVOL), a collection of folders in the file system that exists on each domain controller in a domain and is required for implementation of Group Policy
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What is RAID?
ANS: Redundant Array of Inexpensive disk is a way to increase capaxity, performance and reliablility.
RAID0: (Striping) Not really RAID as it has no fault tolerance, Data is striped across all disks, Excelent read/write performance.
RAID1: (Mirroring) Need at least 2 drives, tolerates single drive failure, often used for OS drive or boot volume.
RAID5: Requires at least 3 drives, data and parity striped across all disks, can tolerate failure of any one disk without losing data but performance does degrade.
TCP/IP MODEL:
Application Layer
Transport Layer
Internet
Network Interface
OSI MODEL
Application Layer
Presentation layer
Session layer
Transport Layer
Network Layer
Data-link Layer
Physical layer
What is a switch?
A network switch, or bridge, is a specialized device that connects multiple network segments. It's a more modern and efficient form of the ubiquitous (and outdated) network hub. A hub, also known as a repeater, is a simple device that has been used for years to connect all nodes, or computers, on a network to a central location. Each node on a network has a unique hardware address called a MAC address. A hub is known as a repeater because when a packet of data, or frame, is sent through the hub, it is repeated to each and every computer on the network.This means that if a 1 GB video is sent to one computer through the hub, the file will also be sent to all of the other computers on the hub. This is very inefficient for bandwidth management. "Hubs have two major drawbacks," says Ben deGonzague, a deployment engineer with TopCoder Software, a Glastonbury, Conn.-based software engineering firm. "First, network bandwidth is consumed as each and every frame is sent to all devices on a network. Second, your network is only as fast as the slowest device. Hubs have become obsolete with switching-based networks."A switch-based network is one that utilizes switches instead of hubs. A switch is a major upgrade to a hub. Instead of sending all network data to each and every network node, the switch will analyze the MAC address and determine where to send the data. Network bandwidth is not wasted by sending every frame to every port.So when a switch receives data for a file, if it was addressed to one computer it will only be sent there. The other computers on the network wouldn't know about it. This means that the network is now much more efficient, but it's also a step toward being more secure: "Since switches can segregate traffic from different nodes," says deGonzague, "this makes it more difficult for anyone to capture packets on your network.
What is a router?
While switches connect multiple computers, a router is required to connect multiple networks, like your LAN to the Internet. Routers work by storing large tables of networks and addresses, then using algorithms to determine the shortest routes to individual addresses within those networks. In this way efficient routers not only facilitate intra-network communications, but also play a role in overall network performance. delivering the information faster.While many consumers are familiar with small routers from companies like Linksys, which can be purchased for less than $50 at computer hardware stores, they shouldn't be confused with a proper router for business. "A typical router at home will connect your cable modem or DSL network to your internal network. This is just connecting two different networks. Routers for businesses on the other hand might have to connect several different networks," says deGonzague. Small business routers from vendors like Cisco often include management software, enabling IT staff to better manage network stability and, ultimately, performance.
1 comment:
thank u friends nice stuff for freshers and every one
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