5 Steps to Fix a Faulty Internet Connection

                                               

                      5 Steps to Fix a Faulty Internet Connection

Whether it's one PC or many, the rules and techniques for troubleshooting Internet problems are basically the same. All it takes is some patience and a bit of common sense. I'll highlight the basic steps to take the next time your small business network fails to connect to the Internet.

Step 1: Restart Your PC and Router

It might sound like the obvious starting point, but you'd be surprised how many people don't try this before sounding the alarm. Yet a simple reboot can actually resolve many of the everyday issues you run into, including a flaky network connection.

Shut down all of the relevant hardware, which includes the PC, the router and the ISP's modem. In some cases the router and modem are integrated into a single unit. And obviously if none of the other PCs in your environment are having this issue you don't need to reset the modem and router, but always try rebooting the computer.

Once you shut down everything, wait at least 5 minutes and restart the devices in this order:

The ISP's modem. Then wait 3 - 5 minutes.

Next restart the router. Again, wait 3 - 5 minutes.

Finally restart your PC, and try to get online.

In most cases, that will do the trick. If not, then you need to search for other possibilities.

Step 2: Isolate the Network Problem

Isolating the problem is not just saying, "I can't get onto the Internet." That's just a symptom or a result of the problem. To resolve it, we need to discover the cause of the problem. How do we do that? Like a good detective, we investigate and ask questions.

For instance, is your machine the only one having the problem, or is it all of the PCs on the network? If it's just your machine then it's probably not the Internet connection itself, but a problem exclusive to your system. On the other hand, if the problem is affecting multiple PCs, then you need to look for other factors, such as how those machines are connected to the Internet. Are they using a wired or wireless connection?

If they all use a wireless connection, then it could be a problem with the access point. If instead they all use a wired connection, then it might be a problem with the switch. If both the wired and wireless PCs are affected, then it could be a problem with the router or the ISP.

In some cases the problem might occur using Internet Explorer, but not when using Google Chrome. This could indicate a problem with the Internet Explorer application itself. In other cases you might not be able to browse the Web, but you can still get email. That would indicate that your Internet connection is fine, but something is blocking HTTP data traveling over port 80, but not email traveling over port 25. This might lead me to suspect a firewall issue or possible virus or malware infection. Once you identify the potential problem area, you can begin troubleshooting.

Step 3: Follow the Network Path

When you have a problem establishing an Internet connection, one of the ways to resolve it is to determine where the communication breakdown is occurring. You can test this by using the Ping command to trace the data path out of your network and to the Internet. To do this, you'll need to know your PC and router/gateway IP addresses.

You find these by running IPCONFIG at the Command Prompt. Typically, the IP address will start with a 192, but 172 and 10 would also be valid. If you find your PC has an IP address beginning with 169, then it is invalid and would explain why you can't get online. This could indicate either a problem with TCP/IP or your router. You can learn more by reading this article about the origin of the 169 address.

If you have a valid IP address, try using the Ping command to verify that your computer can communicate with other systems. Go to the Command Prompt and type ping x.x.x.x where x is the IP address of the device you're trying to reach. You first want to try pinging devices on your network, like other PCs or printers. If you can reach those, try Pinging the gateway.

If you can reach the gateway, try pinging and external site like Google.com or Yahoo.com (example: ping google.com). If that fails, try pinging a couple of public DNS servers such as 4.2.2.2 or 8.8.8.8. If you can successfully ping the public DNS, but not the external site, you might be dealing with a DNS issue. Should that be the case, you could try replacing your current DNS with another one. Here's a list of public DNS servers you could try. If you can't reach either, it could be a problem with your router or ISP

Restoring Internet Connections to Small Business Networks

Step 4: The "X" Factor

The "X" factor is that unknown variable you can't easily identify. When trying to discover the "X" factor you need to ask yourself "what changed on the system before this problem started?" For instance, have you recently installed any new hardware or software? When was the last time you ran a Windows Update? Did it install any new drivers? Were you deleting or uninstalling any applications that might have affected the system? The answers to these types of questions can provide you with important clues for tracking down the source of your problem.

Another "X" factor candidate is a virus or malware infection. In many cases where everything seems to be functioning correctly, yet you still can't get the system online, you may be dealing with a virus. I've seen infections change home pages, prevent certain search engines from loading and even disable Internet Explorer entirely.

In these situations, your best bet is to run a virus scan from outside of the operating system using a rescue CD such as the AVG Rescue CD or the F-Secure Rescue CD. If you're system's infected, these applications should help to expose and expel them.

As a last resort, using Windows built-in System Restore program to revert the system back to an earlier configuration can sometimes be the simplest and quickest way to restore conductivity.

Step 5: Minimize the Complexity

When it comes to troubleshooting, try to keep things as simple as possible. For instance, if you're having problems establishing a wireless connection, it's always best to disable all of the security encryption while attempting to get online. Encryption only adds another layer of complexity to an already complex problem. Get it working first, and then protect it.

In a home-office environment, if you're having trouble getting a PC online and its connected to a router and/or a switch, always connect the modem directly to the PC and verify that the problem still exists. If it does, then the problem lies with the modem or it's a backend problem with your ISP. If however the PC can now get online, then it's most likely a problem with your router. And if the ISP didn't provide it, they're not going to help resolve it.

In this situation, you might just need to replace the router; things do break from time to time. Or it might need updated firmware, or perhaps a reset back to the factory settings. The point is, knowing where to focus your troubleshooting efforts is the best way to get the situation resolved, and the simpler the configuration, the easier it will be to spot the culprit.

Akisha Solutions IT Technical Support: VMware Support in Botswana

Akisha Solutions IT Technical Support: VMware Support in Botswana:



IT Technical Support in Gaborone, Francistown Botswana and India Akisha Solutions Pty Ltd. Providing IT Technical Support 




Computer and networking services to Corporate & Business customers.

What is Vlan ?

                

                        What is Vlan ?

A virtual LAN (VLAN) is any broadcast domain that is partitioned and isolated in a computer network at the data link layer (OSI layer 2). LAN is an abbreviation for local area network. To subdivide a network into virtual LANs, one configures network equipment



What is VLAN Tagging

When VLANs span multiple switches, VLAN Tagging is required. A VLAN is a method of creating independent logical networks within a physical network. VLAN Tagging is the practice of inserting a VLAN ID into a packet header in order to identify which VLAN (Virtual Local Area Network) the packet belongs to.



what is VLAN Trunking Protocol (VTP)

VLAN Trunking Protocol (VTP) is a Cisco proprietary protocol that propagates the definition of Virtual Local Area Networks (VLAN) on the whole local area network. To do this, VTP carries VLAN information to all the switches in a VTP domain. VTP advertisements can be sent over 802.1Q, and ISL trunks.

VLAN Trunking Protocol (VTP) is a Cisco proprietary protocol that propagates the definition of Virtual Local Area Networks (VLAN) on the whole local area network. To do this, VTP carries VLAN information to all the switches in a VTP domain. VTP advertisements can be sent over 802.1Q, and ISL trunks.


what is vlan transparent mode

VTP server is the default mode. Client—VTP clients behave the same way as VTP servers, but you cannot create, change, or delete VLANs on a VTP client. Transparent—VTP transparent switches do not participate in VTP.


what is vtp domain name ?

VLAN Trunking Protocol (VTP) is a Cisco proprietary protocol that propagates the definition of Virtual Local Area Networks (VLAN) on the whole local area network. To do this, VTP carries VLAN information to all the switches in a VTP domain. VTPadvertisements can be sent over 802.1Q, and ISL trunks.

what is vlan promiscuous mode ?

PVLANs provide layer 2 isolation between ports within the same broadcast domain. ... Community— Community ports communicate among themselves and with their promiscuous ports. These interfaces are separated at Layer 2 from all other interfaces in other communities or isolated ports within their PVLAN.


what is interface vlan mode ?

A trunk port can carry traffic in one or more VLANs on the same physical link (VLANs are based on the trunk-allowed VLANs list). By default, a trunk interface can carry traffic for all VLANs. To specify that only certain VLANs are allowed on the specified trunk, use the switchport trunk allowed vlan command.




what is vlan database mode ?

Before creating a VLAN, put the Catalyst 4500 series switch in VTP server modeor VTP transparent mode. If the Catalyst 4500 series switch is a VTP server, you must define a VTP domain. For information on configuring VTP, see "Understanding and Configuring VTP." ... You cannot use Ctrl-Z to exit VLAN database mode.

ACTIVE DIRECTORY CONCEPT

Flexible Single Master Operation (FSMO)

These are the few tasks that are always delegated exclusively to only one single DC of an AD-domain.

Usually in an AD forest with several DCs, there is the rule that all DC tasks can be done by any of the DCs. If there is more than one DC, then any DC that does nothing else but DC can simply be replaced by another DC, and if such a DC fails, this happens automatically, without anything getting lost.

The FSMO roles are the exceptions to this rule. They are the remainder of the older scheme from NT4, where the DCs were not all equal: There had to be one Primary Domain Controller, and all others were Backup Domain Controllers.

In AD there are still a few special tasks that cannot be arbitrarily shared, and that are therefore delegated to one single DC. One example is the allocation of RIDs, because they must be unique. If several DCs would create them, they would have to take special care to never create identical ones. This is much simpler when it is done by only one DC.

Usually all FSMO roles are delegated to the same DC. In a new AD domain the first DC takes all FSMO roles. If that DC is ever replaced, the FSMO roles must be manually transfered to other DCs. For this reason it is important that the admin knows which of the DCs have which of the FSMO roles.

There are five different roles:

• Schema Master (one for the forest)
• Domain Naming Master (one for the forest)
• PDC Emulator (one for each domain)
• RID Master (one for each domain)
• Infrastructure Master (one for each domain)

Partitions. The Active Directory database is organized in partitions, each holding specific object types and following a specific replication pattern. Microsoft often refers to these partitions as 'naming contexts'. The 'Schema' partition contains the definition of object classes and attributes within the Forest.

Active Directory Components

Domains, Organisational units (OUs), domain trees and forests are considered logical structures. Sites and domain controllers are considered physical structures

.

• ·         Domains are the main logical structure in Active Directory because they contain Active Directory objects. Network objects such as users, printers, shared resources, and more are all stored in domains. Domains are also security boundaries. Access Control Lists (ACLs) control access to objects in the domain. The domain functional level enables additional Active Directory features. A user can do this by raising the domain controllers’ domain functional level within the domain. In Windows 2000, the domain mode concept was used and not the domain functional level. The domain functional levels that can be specified are Windows 2000 Mixed, Windows 2000 Native, Windows Server 2003 Interim, and Windows Server 2003.

• ·         Organizational Unit (OU): An OU is a container that enables users to organize objects such as users, computers, and even other OUs in a domain to form a logical administrative group. An OU is the smallest Active Directory component to which users can delegate administrative authority. A domain can have its own unique OU hierarchy.

• ·         Domain Trees: When multiple domains are grouped into a hierarchical structure by adding child domains to a parent domain, a domain tree is being created. Domains are regarded as being part of the same domain tree when they have a contiguous naming structure. A two-way transitive trust relationship is automatically created between the parent domain and child domains when the child domain is created.

• ·         Forests: A forest is the grouping of multiple domain trees into a hierarchical structure. Domain trees in a forest have a common schema, configuration, and global catalog. Domains within the forest are linked by two-way transitive trust. Through the forest functional level, users can enable additional forest wide Active Directory features. The forest functional levels that can be set are Windows 2000, Windows Server 2003 Interim, and Windows Server 2003.

• ·         Sites: In Active Directory, sites are formed through the grouping of multiple subnets. Sites are typically defined as locations in which network access is highly reliable, fast, and not very expensive.

·         Domain Controllers (DCs): A domain controller is a server that stores a write copy of Active Directory. They maintain the Active Directory data store. Certain master roles can be assigned to domain controllers within a domain and forest. Domain controllers that are assigned special master roles are called Operations Masters. These domain controllers host a master copy of particular data in Active Directory. They also copy data to the remainder of the domain controllers. There are five different types of master roles that can be defined for domain controllers. Two types of master roles, forest-wide master roles, are assigned to one domain controller in a forest. The other three master roles, domain-wide master roles, are applied to a domain controller in every domain.

·         The Schema Master is a forest-wide master role applied to a domain controller that manages all changes in the Active Directory schema.

·         The Domain Naming Master is a forest-wide master role applied to a domain controller that manages changes to the forest, such as adding and removing a domain. The domain controller serving this role also manages changes to the domain namespace.

·         The Relative ID (RID) Master is a domain-wide master role applied to a domain controller that creates unique ID numbers for domain controllers and manages the allocation of these numbers.

·         The PDC Emulator is a domain-wide master role applied to a domain controller that operates like a Windows NT primary domain controller. This role is typically necessary when there are computers in one’s environment running pre-Windows 2000 and XP operating systems.

·         The Infrastructure Master is a domain-wide master role applied to a domain controller that manages changes made to group memberships.

Active Directory Schema

The Active Directory schema defines what types of objects can be stored in Active Directory. It also defines what the attributes of these objects are. The following two types of schema objects or metadata define the schema:

·         Schema class objects (schema classes): Define the objects that can be created and stored in Active Directory. The schema attributes store information on the schema class object when a new class is created. A schema class is therefore merely a set of schema attribute objects.

·         Schema attribute objects (schema attributes): Schema attributes provide information on object classes. An object’s attributes are also called the object’ properties.

Although Active Directory includes a large number of object classes, additional object classes can be created if necessary. These additions are known as extensions to the schema. Extensions can only be performed on the domain controller acting the Schema Master role.

The object classes that can be used on access control lists (ACLs) to protect security objects are User, Computer, and Group. These object classes are called security principals. A security principal has a Security Identifier (SID), which is a unique number. A security Principal’s SID consists of the security Principal’s domain and a Relative ID (RID). The RID is a unique suffix.

A few other concepts associated with the Active Directory schema are:

·         Class Derivations: Set a way for forming new object classes with existing object classes.

·         Schema Rules: The Active Directory directory service implements a set of rules into the Active Directory schema that control the manner in which classes and attributes are utilized and what values, classes, and attributes can include. Schema rules are organized into Structure Rules, Syntax Rules, and Content Rules.

·         Structure Rules: The structure rule in Active Directory is that an object class can have only specific classes directly on top of it. These specific classes are called Possible Superiors. Structure rules prevent users from placing an object class in an inappropriate container.

·         Syntax Rules: These rules define the types of values and ranges allowed for attributes.

·         Content Rules dictate what attributes can be associated with a particular class.

Global Catalog

The global catalog is a central information store on the objects in a forest and domain that improves performance when searching for objects in Active Directory. The first domain controller installed in a domain is designated as the global catalog server by default. The global catalog server stores a full replica of all objects in its host domain and a partial replica of objects for the remainder of the domains in the forest. The partial replica contains those objects that are frequently searched for. It is generally recommended to configure a global catalog server for each site in a domain. Active Directory Sites and Services console can be used to set up additional global catalog servers.

Group Policies and Active Directory

Active Directory enables users to perform policy based administration through Group Policy.

 Through group policies, users can deploy applications and configure scripts to execute at startup, shutdown, logon, or logoff. Users can also implement password security, control certain desktop settings, and redirect folders. When users create new group policies in Active Directory, the policy is stored as Group Policy Objects (GPOs). In Active directory, users can apply a GPO to a domain, site, or Organizational Unit.

Active Directory Object Naming Schemes

Each object in the Active Directory data store must have a unique name. Active Directory supports a number of object naming schemes for naming objects:

·         Distinguished name (DN): Each object has a DN. The DN uniquely identifies a particular object and where the object is stored. The components that make up an object’s DN are:

·         CN – common name

·         OU – organizational unit

·         DC – domain component

·         A canonical name is merely a different manner of depicting the object’s DN in a method that is simpler to interpret.

·         Relative distinguished name (RDN): The RDN identifies a particular object within a parent container or OU.

·         Globally unique identifier (GUID): A GUID is a unique hexadecimal number that is assigned to an object at the time that the object is created. The GUID of an object never changes.

·         User principal name (UPN): The UPN is made up of the user account name of the user and a domain name that identifies the domain that contains the user account.

Active Directory Replication

In Active Directory, replication ensures that any changes made to a domain controller within a domain are replicated to all the other domain controllers in the domain. Active Directory utilizes multi-master replication to replicate changes in the Active Directory data store to the domain controllers. With multi-master replication, domains are considered peers to one another.

With Windows Server 2003, the Knowledge Consistency Checker (KCC)creates a replication topology of the forest to ensure that the changes are replicated efficiently to the domain controllers. A replication topology reflects the physical connections that domain controllers use to replicate the Active Directory directory to domain controllers in a site or in different sites. Intra-site replication occurs when the Active Directory directory is replicated within a site. When replication occurs between sites, it is known as inter-site replication.Since the bandwidth between sites is typically slow, information on site link objects identifies the most favorable link that should move replication data between sites in Active Directory.

Active Directory Trust Relationships

In Active Directory, when two domains trust each other or a trust relationship exists between the domains, the users and computers in one domain can access resources in the other domain. The trust relationships supported in Windows Server 2003 are summarized below:

·         Parent/Child trust: A parent/child trust relationship exists between two domains in Active Directory that have a common contiguous DNS namespace and belong to the identical forest. This trust relationship is established when a child domain is created in a domain tree.

·         Tree Root trust: A tree root trust relationship can be configured between root domains in the same forest. The root domains do not have a common DNS namespace. This trust relationship is established when a new tree root domain is added to a forest.

·         Shortcut trust: This trust relationship can be configured between two domains in different domain trees but within the same forest. Shortcut trust is typically utilized to improve user logon times.

·         External trust: External trust relationships are created between an Active Directory domain and a Windows NT4 domain.

·         Realm trust: A realm trust relationship exists between an Active Directory domain and a non-Windows Kerberos realm.

·         Forest trust: A forest trust can be created between two Active Directory forests.

VMware Admin Daily Activities

     VMware Admin Daily Activities

1.    Check the health of all Hosts and VM objects in vCenter.

2.    Are there any active alarms in vCenter?

3.    Have you set up any alarms in the first place?

4.    Do the alarms automatically trigger notification or any type of incident tracking mechanism?

5.    Are all vCenter plug-ins functioning properly?

6.    Do you have any Host Hardware issues? Alarms, bad memory, power supply or capacity issues?

7.    Are all Hosts in compliance with Host Profiles?

8.    Are there any resource bottlenecks? Memory, CPU, Disk, Network? Do you have any, or need any, additional tools 
to have a better handle on this?

9.    Are you running at your optimum resource levels? In other words, is the load properly distributed?

10.  Are you running out of resources anywhere? LUNs with low disk space, etc. Do you need to start looking at budgeting for additional capacity?

11.  Check for Firmware updates on Host hardware

12.  Check for ESX Patches

13.  Check for VM Patches

14.  Check VMware Tools version

15.  Run scripts to identify the existence of VMs with snapshots and follow up to see if they are still needed.

16.      Have you schmoozed with your Storage Admins lately? A good idea since you cannot get very far without them.

Networking Concepts

        Removing VLANs

Follow the steps below to remove VLANs switches.

Step Command Description

Step 1 configure terminal Enter the configuration mode

Step 2 no vlan <vlan-list>

Remove VLANs using the no vlan
command.

vlan-list – may be any vlan number or

list of vlan numbers. Multiple vlan

numbers can be provided as comma

separated list. Consecutive vlan

numbers can be provided as ranges like
5-10.

Step 3 show vlan To display the configured VLANs

Step 4 write startup-config Optional step – Save these VLAN
configuration to be part of startup
configuration.

The below examples show sample ways to remove VLANs.

Delete a VLAN with identifier 10

SMIS# configure terminal

SMIS(config)# no vlan 10

Delete VLANs with identifier 20 to 30, 50 and 100
SMIS# configure terminal

SMIS(config)# no vlan 20-30,50,100

SMIS(config-vlan)# exit




 VLAN Name
VLANs can be associated with a label name string for easier configuration and identification.
Follow the steps below to add or modify a name string to any VLAN in Supermicro switches.
VLAN Configuration Guide




Step Command Description

Step 1 configure terminal Enters the configuration mode.

Step 2 vlan <vlan-list>

Enters the VLAN configuration mode.

vlan-list – may be any VLAN number or
list of VLAN numbers. Multiple VLAN
numbers can be provided as commaseparated
values. Consecutive VLAN
numbers can be provided as a range,
such as 5-10.
If multiple VLANs are provided, the
same name string provided in next step
will be associated with all these VLANs.
Step 3 name <vlan-name-string> Associates a name string to this VLAN
using the name command.
vlan-name-string is any alphanumeric
string up to 32 characters.
Step 4 show vlan Displays the configured VLANs
Step 5 write startup-config Optional step – saves this VLAN
configuration to be part of startup
configuration.
The example below shows the necessary steps to associate a name string to a VLAN.
Associate name main_user_vlan to VLAN 50.

Active Directory Questions and Answers.

   Active Directory Questions and Answers. 

1. What is an IP Address? It is 32 Bits binary number (or any brief answer you can come up with) If you are spending to explain 5 minutes what an IP address is, that is not good at all.

2. What is Subnet Mask? IT is also 32 Bits Binary number

3. What does subnet mask do? It divides IP address into two distinct part, Network and Host portion.

4. Provide full subnet mask for /27 255.255.255.224 /27 means 27 bits turned on, 8 bits = 255 24 bits = 255.255.255 3 bits 128 + 64 + 32 = 224 Therefore, full SB mask for /27 is 255.255.255.224 If you did not get this STOP. You need to go back and learn basic subnetting. You cannot screw up with such easy question on the interview, so take your time to study. (Special Thanks to My body Zack Payton for making me understand many years ago)

5. Now it is rare in the AD Interview but incase, you could be asked /27 how many network and how many hosts in each network? Going back to basic, /27 255.255.255.0 3 bits for network 5 bits for Hots 2X2X2 = 8 Networks 2x2x2x2x2 = 30 Hosts in each Networks (32 -2 = 30) we need one IP for each Network and another one for Broadcast.


6. What is an Active Directory? It is a database (Active Directory is a special-purpose database)

7. What is an object An object is an instance of storage of a class, user is an object, computer account is also an object etc.

8. What is an attribute? Property of an Object called an attribute, think of user object, and think of all available attributes associating with user object, name, last name, logon name etc.

9. What is the name of Active Directory Database, when you install Domain Controller, by default directory database gets created? Active Directory database is. DIT database, it is NTDS.dit


10. NTDS.DIT Database is partitioned database, what are the partitions on it? 1. Domain 2. Configuration 3. Schema 4. Application (if created)

11. What tool can interact with (. DIT) database (the most common) adsiedit.msc

12. In Which directory partition DNS information is kept? Domain Partition

13. In Which partition Exchange Server information is kept (tricky question) All of the partitions. 1. Domain 2. Configuration 3. Schema

14. What is DNS Domain Name System, Service

15. What port DNS runs on 53

16. Is it TCP or UDP Both are protocols

17. What is TCP Transmission Control Protocol 18. What is UDP User Datagram Protocol

19. What is the difference in between TCP /UDP Protocols? TCP is connection oriented, whereas UDP is connectionless

20. How many Bytes TCP Header? Size of TCP Header (without any options) - 20 Bytes


21. How many Bytes UDP Header? Size of UDP header - 8 bytes

22. Size of Total empty TCP datagram Total size of empty TCP datagram - 24 + 20 + 20 = 64 bytes  Size of Ethernet frame - 24 Bytes  Size of IPv4 Header (without any options) - 20 bytes  Size of TCP Header (without any options) - 20 Bytes 5 | P a g e Visit my Blog

23. Size of Total empty UDP datagram Total size of empty UDP datagram - 24 + 20 + 8 = 52 bytes  Size of UDP header - 8 bytes  Size of Ethernet frame - 24 Bytes  Size of IPv4 Header (without any options) - 20 bytes

24. Considering single Forest with 12 domains, how many FSMO role in total exist? Total FSMO roles in this scenario = 38  12 X 3 = 36 (PDC, RID, Infrastructure) Master  2 For each Forest (Domain Naming Master and Schema Master per Forest)  Total = 38

25. What is FSMO? Flexible Single Master Operations How many FSMO role exist?

26. What is the least important FSMO role, considering day to day operations which one of FSMO role absence would be least significant impact and Why? Perhaps Schema Master if you assume you don’t extend your schema every day or RID master

27. What is the most important FSMO role, considering day to day operations which one of FSMO role absence would be most significant impact and why? PDC Emulator (explain why)

28. What is the difference in between seizing and moving FSMO roles? Peaceful operation versus forcing it. Seizing is the operation when FSMO role owner is no longer accessible and after seizing FSMO roles, you cannot bring the previous FSMO role owner back to network.

29. What is an A record, when I open A record what do I see inside? Host name mapping to IPV4 record

30. What is an AAA record, when I open A record what do I see inside? Host name mapping to IPV6 record

31. What is Glue record, when I open A record what do I see inside? Simply Host name mapping to IP address (same as A record)

32. What is PTR record, when I open A record what do I see inside? Pointer record, IP address map to Host name

33. What is CNAME record, when I open A record what do I see inside? Chomical Name record, Multiple names mapping to same IP address

34. What is Alias record, when I open A record what do I see inside? Another name for CNAME record, Multiple names mapping to same IP address


35. What is a SRV record? Service record, which provides information about service and port information

36. How many reverse lookup zone, is available with default DNS installation? None, DNS does not relay on reverse DNS zone to work properly. It is optional to crate reverse DNS zone, and many administrators will recommend creating one for various reasons (security etc.)

37. How many forward lookup zone, is available with default DNS Installation? Single forward lookup zone gets created with default installation of DNS services on a Domain Controller. 38. What is an OU Organization Unit

39. What are three primary functions of Organizational Units? Organize Data, Deploy GPO, Delegate permissions (We use AD Groups to assign permissions to not get confused and be precise with your answer)

40. In which order OU’s are being applied in Active Directory  Local  Site  Domain  Organization Unit

41. If you have one OU and you have mixed server in it (Windows 2008 and Windows 2012 servers) How do, I apply GPO to only Windows 2012 Servers. Assuming I cannot create any new OU. Use WMI filtering and only target specific Windows Server version

42. If you have lost one of the domain controllers how do you clean up Active Directory database for the lost DC? Meta Data Cleanup with Ntdsutil.exe is a command-line tool

43. What is KCC and what does it do? Knowledge Consistence Checker, it builds replication connections in between domain controllers

44. What is LSAS Lsass.exe (Local Security Authority Subsystem Service) is the process which, on an Active Directory domain controller, is responsible for providing Active Directory database lookups, authentication, and replication


45. What kind of replication Active Directory uses? is it pull or push? Active Directory uses pull replication. In pull replication, a destination replica requests information from a source replica. The request specifies the information that the destination needs, based on its knowledge of changes already received from the source and from all other domain controllers in the domain. When the destination receives information from the source, it applies that information, bringing itself more up-to-date. The destination's next request to the source excludes the information that has already been received and applied. The alternative is push replication. In push replication, a source sends information to a destination unsolicited, in an attempt to bring the destination more up-to-date. Push replication is problematical because it is difficult for the source to know what information the destination needs. Perhaps the destination has received the same information from another source. If a source sends information to a destination, there is no guarantee that the destination is going to apply it; if the source assumes otherwise, the system is unreliable.