How To Generate All Domain Controllers in Active Directory

In this article, we’ll describe how to generate all Domain Controllers in the Active Directory Sites and Services tool.

Active Directory Sites and Services can be seen as an administrative tool used to manage sites and the related components on Microsoft Server systems.

It contains a list of all Domain Controllers (DCs) connected to the system, regardless of their number.

In some situations, admins can notice more than one DC listed under Windows NT Directory Services (NTDS) settings.

What are these other DCs, and how can they be generated automatically?

KCC

Those DCs are called KCCs (Knowledge Consistency Checkers). They are nominated bridgehead servers per site that handle replication tasks between specific sites.

A bridgehead server is responsible for replicating any changes to all remaining DCs in its site.

In simple words, KCCs take care of replication by generating DCs, which communicate with other DCs and KCCs—consequently, the auto-generated domain controllers take care of the replication.

How to create automatically generated Domain Controllers

There are instances, such as during server moves or adding new organizational Domain Controllers, when   Active Directory is unable to create ‘Automatically Generated’ connections with the root Domain Controller.

In such a situation, the Domain Controller can be seen, but not on the “real” Domain Controller list.

There is more than one solution to this problem.

Let’s talk about two of the most used and tested solutions.

1. Manually forcing auto generation

This first method, although it can get in the quick “workaround” category,  involves manually forcing auto-generation.

It can be done by right clicking on the NTDS Settings option and then choosing ‘All Tasks and Check Replication Topology’ in the end.

That should force trigger auto-generation of all Domain Controllers, and your Domain Controllers should now be visible on the list.

2. Repadmin

Repadmin is a command line tool used for diagnosing and repairing replication problems.

It can be used from an elevated command prompt by typing ntdsutil.

Then, entering this command:

repadmin / showrepl*

To create an output that replicates the state of all DCs in the system, enter this command:

Repadmin/replicate

As a result, force replication will be started. This command forces replication and generates all Domain Controllers on the Sites and Services list.

Conclusion

It is usually not necessary to create manual connections when the KCC is being used to generate automatic connections; if any conditions change, the KCC automatically reconfigures the connections.

Adding manual connections when the KCC is employed can potentially increase replication traffic and conflicts with optimal settings stipulated by KCC.

If a connection is not working due to a failed domain controller, the KCC automatically builds temporary connections to other replication sites (if the damage is not too big) to ensure that replication occurs.

If all the domain controllers in a site are unavailable, KCC automatically creates replication connections between domain controllers from another site.

It is not recommended to manually modify this, unless you have a very specific use case.

As long as these records are auto-generated, they can survive a Domain Controller failure, as the KCC/ISTG will automatically create a new connection.

However, if you manually create a connection or specify a bridgehead server, and that server goes offline, KCC will not create a new connection and replication between the affected sites will stall.

How to Set Accurate Time for Windows Server 2016

Accurate Time For Windows Server 2016

It is important for Windows Server 2016 to maintain an accuracy of 1ms in sync with the UTC time. This is because new algorithms and periodic time checks are obtained from a valid UTC server.

The Windows time service is a component that uses a plugin for the client and server for synchronization.

Windows has two built-in client time providers that link with the third party plugins.

One of the providers uses the Network Time Protocol (NTP) or the Microsoft Network Time Protocol (MS-NTP) to manage the synchronizations to the nearest server.

Windows has a habit of picking the best provider if the two are available.

This article will discuss the three main elements that relate to an accurate time system in Windows Server 2016:

  • Measurements
  • Improvements
  • Best practices

Domain Hierarchy

Computers that are members of a domain use the NTP protocol that authenticates to a time reference in relating to security and authenticity.

The domain computers synchronize with the master clock that is controlled by domain hierarchy and the scoring system.

A typical domain has hierarchical stratum layers where each Domain Controller (DC) refers to the parent DC with accurate time.

The hierarchy revolves around the Primary Domain Controller (PDC) or a DC with the root forest, or a DC with a Good Time Server for the Domain (GTIMESERV) flag.

Standalone computers use the time.windows.com service. The name resolution takes place when the Domain Name Service resolves to a time owned by a Microsoft resource.

Like any other remotely located time references, network outages do not allow synchronization to take place. Paths that are not symmetrical in a network reduce time accuracy.

Hyper-V guests have at least two windows time providers; therefore, it is possible to observe different behaviors with either the domain or the standalone.

NOTE: stratum refers to a concept in both the NTP and the Hyper-V providers. Each has a value indicating clock location in the hierarchy. Stratum 1 is for high-level clock, and stratum 0 is for hardware. Stratum 2 servers communicate to stratum 1 servers, stratum 3 to stratum 2, and the cycle continues. The lower strata show clocks that are more accurate with the possibility of finding errors. The command line tool w32tm (W32time) takes time from stratum 15 and below.

Factors Critical For Accurate Time

1. Solid Source Clock

The original source of the clock needs to be stable and accurate at all times. This implies that during the installation of the Global Positioning Service (GPS) pointing to stratum 1, you should take #3 into consideration.

Therefore, if the source clock shows stability, then the entire configuration will have a constant time.

Securing the original source time means that a malicious person will not be able to expose the domain to time-based threats.

2. Stable Client Clock

A stable client takes the natural drift of the oscillator to make sure that it is containable. The NTP uses multiple samples to condition the local clocks on standalone to stay on course.

If the time oscillation on the client computers is not stable, there will be fluctuations between adjustments leading to malfunctioning of the clock.

Some machines may require hardware updates for proper functioning.

3. Symmetrical NTP Communication

The NTP connection should be symmetrical at all times because the NTP uses calculation adjustments to set time as per the symmetry levels.

If the NTP request takes longer than the expected time on its return, time accuracy is affected. You may note that the path could change due to changes in topology or routing of packets through different interfaces.

The battery-powered devices may use different strategies, which in some cases require that the device be updating every second.

Such a setting consumes more power and can interfere with power saving modes. Some battery run devices have some power settings that can interfere with the running of other applications and hence interfere with the W32time functions.

Mobile devices are never 100% accurate, especially if you look at the various environmental factors that interfere with the clock accuracy. Therefore, battery-operated devices should not have high time accuracy settings.

Why is Time Important

A typical case in a Windows environment is the operation of the Kerberos that needs at least 5 minutes accuracy between the clients and servers.

Other instances that require time include:

  • Government regulations, for example, the United States of America uses 50ms for FINRA, and the EU uses 1ms ESMA or MiFID II.
  • Cryptography
  • Distributed systems like the databases
  • Block chain framework for bitcoin
  • Distributed logs and threat analysis
  • AD replication
  • The Payment Card Industry (PCI)
  • The Time Improvements for Windows Server 2016
  • Windows Time Service and NTP

The algorithm used in Windows Server 2016 has greatly improved the local clock when synchronizing with the UTC. The NTP has four values to calculate the time offset based on timestamps of client requests or responses and server requests and responses.

The modern network environment has too much congestion and related factors that affect the free flow of communication.

Windows Server 2016 uses different algorithms to cancel out the disturbances. Besides, the source used in Windows for time references uses improved Application Programming Interface (API) with the best time resolution, giving an accuracy of 1ms.

Hyper-V

Windows 2016 Server made some improvements that include accurate VM start and VM restore. The change gives us an accuracy of 10µs of the host with a root mean square (RMS) of 50µs for a machine carrying a 75% load.

Moreover, the stratum level at the host sends to guests more transparently. Earlier hosts would be fixed at stratum 2, regardless of its accuracy and the changes in Windows Server 2016 the host reports at stratum 1, which gives better timing for the virtual machines.

Domains created in Windows 2016 Server will find time to be more accurate because the time does not default to the host and that is the reason behind manually disabling the Hyper-V time provider settings in Windows joining a Windows 2012R2 and below.

Monitoring

Counters tracking the performance counters are now part of the Windows Server 2016, they allow for monitoring, troubleshooting, and baselining time accuracy.

The counters include:

a. Computed Time Offset

This feature indicates the absolute time between the system clock and the chosen time source in microseconds. The time updates whenever a new valid sample is available. Clock accuracy is traced using the performance counter that has an interval of 256 seconds or less.

b. Clock Frequency Adjustment

This adjustment indicates the time set by the local W32Time measured in parts per billion. The counter is important when it comes to visualizing actions taken by W32time.

c. NTP Roundtrip Delay

NTP Roundtrip Delay is the time taken during the transmission of a request to the NTP server and when the response is valid.

This counter helps in characterizing the delays experienced by the NTP client. If the roundtrip is large or varies, it can lead to noise, especially when the NTP computes time, thereby affecting time accuracy.

d. NTP Client Source Count

The source count parameter holds the number of clients and unique IP addresses of servers that are responding to client requests. The number may be large or small compared to active peers.

e. NTP Server Incoming Requests

A representation of the number of requests received by the NTP server indicated as request per second.

f. NTP Server Outgoing Responses

A representation of the number of answered requests by the NTP server indicated as responses per second.

The first three show the target scenarios for troubleshooting accuracy issues. The last three cover NTP server scenarios, which help to determine the load and setting a base for the current performance.

Configuration Updates per Environment

The following is a description that changes the default configurations between Windows 2016 and earlier versions.

The settings for Windows Server 2016 and Windows 10 build 14393 are now taking unique settings.

Role

Settings

Server 2016

Windows 10

Servers 12 and 08 and Windows 10

Standalone or a Nano Server

    
 

Time server

time.windows.com

N/a

time.windows.com

 

Poling frequency

64-1024 seconds

N/a

Once a week

 

Clock update frequency

Once a second

N/a

Once a hour

Standalone Client

    
 

Time server

N/a

time.windows.com

time.windows.com

 

Polling frequency

N/a

Once a day

Once a week

 

Clock update frequency

N/a

Once a day

Once a week

Domain Controller

    
 

Time server

PDC/GTIMESERV

N/a

PDC/GTIMESERV

 

Polling frequency

64 to 1024 seconds

N/a

1024 to 32768 seconds

 

Clock update frequency

Once a day

N/a

Once a week

Domain Member Server

    
 

Time server

DC

N/a

DC

 

Polling frequency

64 to 1024 seconds

N/a

1024 to 32768 seconds

 

Clock update frequency

Once a second

N/a

Once every 5 minutes

Domain Member Client

    
 

Time server

N/a

DC

DC

 

Polling frequency

N/a

1024 to 32768 seconds

1024 to 32768 seconds

 

Clock update frequency

N/a

Once every 5 minutes

Once every 5 minutes

Hyper-V Guest

    
 

Time server

Chooses the best alternative based on host stratum and time on the server

Chooses the best alternative based on host stratum and time server

Defaults to host

 

Polling frequency

Based on the role above

Based on the role above

Based on the role above

 

Clock update frequency

Based on the role above

Based on the role above

Based on the role above

Impact of Increased Polling and Clock Update Frequency

To get the most accurate time, the defaults for polling frequencies and clock updates will give you the ability to make adjustments more frequently.

The adjustments lead to more UDP and NTP traffic that will in no way affect the broadband links.

Battery devices do not store the time when turned off, and when turned on, it may lead to frequent time adjustments. Increasing the polling frequency will lead to instability, and the device will use more power.

Domain controllers should have less interference after multiple effects of increasing updates from NTP clients and AD domain. NTP does not require many resources compared to other protocols.

You can reach the limits of the domain functionality before getting a warning, indicating increased settings in Windows Server 2016.

The AD does not use secure NTP, which does not synchronize time accurately but will increase the clients two strata away from the PDC.

You can reserve at least 100NTP requests per second for every core. If you have a domain with 4 CPUs each, the total NTP should be serving 1,600 NTP requests per second.

As you set up the recommendations, ensure you have a large dependency on the processor speeds and loads. Administrators should conduct all baseline tests onsite.

If your DCs are running on sizeable CPU load of more than 40%, the system is likely to generate some noise when NTP is responding to requests, which may impair domain time accuracy.

Time Accuracy Measurements

Methodology

Different tools can be used to gauge the time and accuracy of Windows Server 2016.

The techniques are applicable when taking measurements and tuning the environment to determine if the test outcome meet the set requirements.

The domain source clock has two precision NTP servers and GPS hardware.

Some of these tests need a highly accurate and reliable clock source as a reference point adding to your domain clock source.

Here are four different methods for measuring accuracy in physical and virtual machines:

  • Take the reading of the local clock conditioned by a w32tm and reference it against a test machine with a separate GPS hardware.
  • Measure pings coming from the NTP server to its clients using the “stripchart” of the W32tm utility
  • Measure pings from the client to the NTP server using “stripchart” of the W32tm utility.
  • Measure the Hyper-V output from the host to the guests using the Time Stamp Counter (TSC). After getting the difference of the host and client time in the VM, use the TSC to estimate the host time from the guest. We also consider the use of TSV clock to factor out delays and the API latency.

Topology

For comparison purposes, testing both the Windows Server 2012R2 and Windows Server 2016 based on topology is sensible.

The topologies have two physical Hyper-V hosts that point to a 2016 Server with a GPS hardware installed. Each of these hosts runs at least three domains joining the Windows guests, taking the arrangement shown in the diagrams below.

TOPOLOGY 1. Image Source

The lines on the diagram indicate time hierarchy and the transport or protocol used.

TOPOLOGY 2. Image Source

Graphical Results Overview

The following graph is a representation of the time accuracy between two members of a domain. Every graph shows both Windows Server 2012R2 and 2016 outcome.

The accuracy was a measurement taken from the guest machine in comparison to the host. The graphical data shown indicate both the best and worst case scenarios.

TOPOLOGY 3. Image Source

Performance of the Root Domain PDC

The root PDC synchronizes with the Hyper-V host using a VMIC that is present in Windows Server 2016 GPS hardware, which shows stability and accuracy. This is critical because a 1ms accuracy is needed.

Performance of the Child Domain Client

The child domain client is attached to a Child Domain PDC for sending communication to the Root PDC. Its timing should also be within the 1ms accuracy.

Long Distance Test

Long distance test could involve comparing a single virtual network hop to 6 physical network hops on Windows Server 2016.

Increasing network hops mean increasing latency and extending time differences. The 1ms accuracy may negatively change, which demonstrates a symmetrical network.

Do not forget that every network is different and measurements taken depend on varying environmental factors.

Best Practices for Accurate Timekeeping

1. Solid Source Clock

The machine timing is as good as its source clock. To achieve the 1ms accuracy, a GPS hardware or time appliance should be installed to refer to the master source clock.

The default time.windows.com may not give an accurate or stable local time source. Also, as you move away from the source clock, you are bound to lose time.

2. Hardware GPS Options

The different hardware solutions that offer accurate time depend on GPS antennas. Use of radio and dial-up modem solutions is also accepted. The hardware options connect through PCIe or USB ports.

Different options give varying time accuracy and the final time depends on the environment.

Environmental factors that interfere with accuracy depends on GPS availability, network stability, the PC hardware and network load.

3. Domain and Time Synchronization

Computers in a domain use the domain hierarchy to determine the machine to be used as a source for time synchronization.

Every domain member will look for a machine to sync with and save it as its source. Every domain member will follow a different route that leads to its source time. The PDC in the Forest Root should be the default source clock for all machines in the domain.

Here is a list of how roles in the domain find their original time source.

  • Domain Controller with PDC role

This is the machine with authority on time source for the domain. Most of the time, its issues are accurate and must synchronize with the DC in the parent domain–with exceptional cases where GTIMESERV role is active.

  • Other Domain Controller

This will take the role of a time source for clients and member servers in the domain. A DC synchronizes with the PDC of its domain or any DC in the parent domain.

  • Clients or Member Servers

This type of machine will synchronize with any DC or PDC within its domain or picks any DC or PDC in the parent domain.

When sourcing for the original clock, the scoring system is used to identify the best time source. Scoring takes into account the reliable time source based on the relative location, which happens only once when the time service starts.

To fine-tune time synchronization, add good timeservers in a specific location and avoid redundancy.

Mixed Operating System Environments (Windows 2012 R2 and Windows 2008 R2)

In a pure Windows Server 2016 domain environment, you need to have the best time accuracy.

Deploying a Windows Server 2016 Hyper-V in a Windows 2012 domain will be more beneficial to the guests because of the improvements made in Server 2016.

A Windows Server 2016 PDC delivers accurate time due to the positive changes to its algorithms, which also acts as a credible source.

You may not have an option of replacing the PDC, but you can add a Windows Server 2016 DC with the GTIMESERV flag as one way of upgrading time accurately for the domain.

Windows Server 2016 DC delivers better time to lower clients, but it’s always good to use it as a source NTP time.

As already stated above, clock polling and refresh frequencies are modified in Windows Server 2016.

You can also change the settings manually to match the down-level DCs or make the changes using the group policy.

Versions that came prior to Windows Server 2016 have a problem with keeping accurate time since their systems drift immediately you make a change.

Obtaining samples from accurate NTP sources and conditioning the clock leads to small changes in system clock, ensuring better time keeping on the low-level OS versions.

In some cases involving the guest domain controllers, samples from the Hyper-V TimeSync is capable of disrupting time synchronization. However, for Server 2016, it should no longer be an issue when the guest machines run on Server 2016 Hyper-V hosts.

You can use the following registry keys to disable the Hyper-V TimeSync service from giving samples to w32time:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W32Time\TimeProviders\VMICTimeProvider

“Enabled”=dword:00000000

Allow Linux to Use Hyper-V Host Time

For guest machines using Linux and run the Hyper-V, it is normal for clients to use the NTP Daemon for time synchronization against the NTP servers.

If the Linux distribution supports version 4 TimeSync protocol with an enabled TimeSync integration on the guest, then synchronization will take place against the host time. Enabling both methods will lead to inconsistency.

Administrators are advised to synchronize against the host time by disabling the NTP time synchronization by using any of the following methods:

  • Disabling NTP servers in the ntp.conf file
  • Disabling the NTP Daemon

In this particular configuration, the Time Server Parameter is usually the host, and it should poll at a frequency of 5 seconds, which is the same as the Clock Update Frequency.

Exclusive synchronization over NTP demands that you disable the TimeSync integration service in the guest machine.

NOTE: Linux accurate timing support must have a feature supported in the latest upstream Linux Kernels. As at now, it is not available across most Linux distros.

Specify Local Reliable Time Service Using the GTIMESERV

The GTIMESERV allows you to specify one or more domain controllers as the accurate source clocks.

For example, you can use a specific domain controller with a GPS hardware and flag it as GTIMESERV to make sure that your domain references to a clock based on a GPS hardware.

TIMESERV is a Domain Services Flag that indicates whether the machine is authoritative and can be changed if the DC loses connection.

When the connection is lost, the DC returns the “Unknown Stratum” error when you query via the NTP. After several attempts, the DC will log System Event Time Service Event 36.

When configuring a DC as your GTIMESERV, use the following command:

w32tm /config /manualpeerlist:”master_clock1,0x8 master_clock2,0x8” /syncfromflags:manual /reliable:yes /update

If the DC has a GPS hardware, use the following steps to disable the NTP client and enable the NTP server:

reg add HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\w32time\TimeProviders\NtpClient /v Enabled /t REG_DWORD /d 0 /f

reg add HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\w32time\TimeProviders\NtpServer /v Enabled /t REG_DWORD /d 1 /f

Then, restart Windows Time Service

net stop w32time && net start w32time

Finally, tell network hosts that this machine has a reliable time source using this command:

w32tm /config /reliable:yes /update

Confirm the changes, run the following commands, which indicate the results as shown:

w32tm /query /configuration

Value

Expected Setting

AnnounceFlags

5 (Local)

NtpServer

(Local)

DIIName

C:\WINDOWS\SYSTEM32\w32time.DLL (Local)

Enabled

1 (Local)

NtpClient

(Local)

w32tm /query /status /verbose

Value

Expected Setting

Stratum

1 (primary reference – syncd by radio clock)

ReferenceId

0x4C4F434C (source name: “LOCAL”)

Source

Local CMOS Clock

Phrase Offset

0.0000000s

Server Role

576 (Reliable Time Service)

Windows Server 2016 on 3rd party Virtual Platforms

The virtualization of Windows means that the time responsibility defaults to the Hypervisor.

However, new members of the domain need to be synchronized with the Domain Controller for the AD to work effectively. The best that you can do is to disable time virtualization between guests and 3rd party virtual platforms.

Discover the Hierarchy

The chain of time hierarchy to the master clock is dynamic and non-negotiated. You must query the status of a specific machine to get its time source. This analysis helps in troubleshooting issues relating to synchronizations.

If you are ready to troubleshoot, find the time source by using the w32tm command:

w32tm /query /status

The output will be the source. Finding the source is the initial step in time hierarchy.

The next thing to do is to use the source entry and /Stripchart parameter to find the next time source.

w32tm /stripchart /computer:MySourceEntry /packetinfo /samples:1

The command below gives a list of domain controllers found in a specific domain and relays the results that you can use to determine each partner. The command also includes machines with manual configurations.

w32tm /monitor /domain:my_domain

You can use the list to trace the results through the domain and know their hierarchy and time offset at each step.

If you mark the point where time offset increases, you can get to know the cause of incorrect time.

Using Group Policy

Group policy is used to accomplish strict accuracy by making sure clients are assigned specific NTP servers. Clients can control how down-level OS should work when virtualized.

Look at the following list of all possible scenarios and relevant Group Policy settings:

  • Virtualized Domains

To gain control over the Virtualized Domain Controllers in Windows 2012 R2, disable the registry entry corresponding to the virtual domain controllers.

You may not want to disable the PDC entry because in most cases, Hyper-V host delivers a stable time source. The entry to the registry requires that you restart the w32time service after making changes.

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W32Time\TimeProviders\VMICTimeProvider]

“Enabled”=dword:00000000

  • Accuracy Sensitive Loads

For any workload that is sensitive to time accuracy, ensure that the group machines are set to use the NTP servers and any related time settings like update frequency and polling.

This is a task handled by a domain, but if you want to have more control, target specific machines to point to the master clock

Group Policy Setting

New Value

NtpServer

ClockMasterName,0x8

MinPollInterval

6-64 seconds

MaxPollInterval

6 seconds

UpdateInterval

100 to once per second

EventLogFlags

3 – All special time logging

NOTE: The NtpServer and EventLogFlags are located on the System\Windows Time Service\Time Providers, if you follow the Configure Windows NTP Client Settings. The other three are under the System\Windows Time Service, if you follow the Global Configuration Settings

Remote Accuracy Sensitive Loads Remote

For systems running on the branch domains, such as the Retail and Payment Credit Industry (PCI), Windows will use the current site data and DC Locator to search the local DC, unless you have a manual NTP time source configured.

In such an environment, you need 1 second accuracy with the option of using the w32time services to move the clock backwards.

If you can meet the requirements, use the table below to create a policy.

Group Policy Settings

New Value

MaxAllowedPhaseOffset

1, if more than on second, set clock to correct time.

The MaxAllowedPhaseOffset is a setting you will find under System\Windows Time Service using global Configuration settings.

Azure and Windows IaaS Consideration

  • Azure Virtual Machine: Active Directory Domain Services

If you have Azure VM running Active Directory Domain Services as part of the existing configuration in a Domain Forest, then the TimeSync (VMIC) should not be running.

Disabling VMIC allows all DCs in both physical and virtual forests to use a single time sync hierarchy.

  • Azure Virtual Machine: Domain –Joined Machine

If you have a host whose domain links to an existing Active Directory Forest, whether virtual or physical, the best you can do is to disable TimeSync for the guest and make sure the W32Time is set to synchronize with the Domain Controller.

  • Azure Virtual Machine: Standalone Workgroup Machine

If your Azure is not part of a domain and it is not a Domain Controller, you can keep the default time configuration and let the VM synchronize with the host.

Windows Applications that Require Accurate Time

Stamp API

Programs or applications that need time accuracy in line with the UTC should use the GetSystemTimePreciseAsFileTime API to get the time as defined by Windows Time Service.

UDP Performance

An application that uses UDP to communicate during network transactions should minimize latency. You have the registry options to use when configuring different ports. Note that any changes to the registry should be restricted to system administrators.

Windows Server 2012 and Windows Server 2008 need a Hotfix to avoid datagram losses.

Update Network Drivers

Some network cards have updates that help improve performance and buffering of UDP packets.

Logging for System Auditors

Time tracing regulation may force you to comply by archiving the w32tm logs, performance monitors, and event logs. Later, these records may be used to confirm your compliance at a specific time in the past.

You can use the following to indicate time accuracy:

  • Clock accuracy using the computed time offset counter
  • Clock source looking for “peer response from” in the w32tm event logs
  • Clock condition status using the w32tm logs to validate the occurrence of “ClockDispl Discipline:*SKEW*TIME*.”

Event Logging

An event log can give you a complete story in the information it stores. If you filter out the Time-Server logs, you will discover the influences that have changed the time. Group policy can affect the events of the logs.

W32time Debug Logging

Use the command utility w32tm to enable audit logs. The logs will show clock updates as well as the source clock.

Restarting the service enables new logging.

Performance Monitor

The Windows Server 2016 Time service counters can collect the logging information that auditor’s need. You can log the data locally or remotely by recording the machine’s Time Offset and Round Trip Delays.

Like any other counter, you can create remote monitors and alerts using the System Center Operations Manager. You can set an alert for any change of accuracy when it happens.

Windows Traceability Example

Using sample log files from the w32tm utility, you can validate two pieces of information where the Windows Time Service conditions the first log file at a given time.

151802 20:18:32.9821765s – ClockDispln Discipline: *SKEW*TIME* – PhCRR:223 CR:156250 UI:100 phcT:65 KPhO:14307

151802 20:18:33.9898460s – ClockDispln Discipline: *SKEW*TIME* – PhCRR:1 CR:156250 UI:100 phcT:64 KPhO:41

151802 20:18:44.1090410s – ClockDispln Discipline: *SKEW*TIME* – PhCRR:1 CR:156250 UI:100 phcT:65 KPhO:38

All the messages that start with “ClockDisplin Discipline” are enough proof that your system is interacting with the system clock via the w32time.

The next step is to find the last report before the time change to get the source computer that is the current reference clock.

Like in the example below, we have the Ipv4 address of 10.197.216.105 as the reference clock. Another reference could point to the computer name or the VMIC provider.

151802 20:18:54.6531515s – Response from peer 10.197.216.105,0×8 (ntp.m|0x8|0.0.0.0:123->10.197.216.105:123), ofs: +00.0012218s

Now that the first section is valid, investigate the log file on the reference time source using the same steps.

This will give you a physical clock such as the GPS or a known time source like the National Institute of Standards and Technology (NIST). If the clock is a GPS hardware, then manufacturer logs may be required.

Network Considerations

The NTP protocol algorithm depends on the network symmetry, making it difficult to predict the type of accuracies needed for certain environments.

You an use the Performance Monitor and new Windows Time Counters for Windows Server 2016 to create baselines.

The Precision Time Protocol (PTP) and the Network Time Protocol (NTP) are the two that you can use to gauge accurate time.

If clients are not part of a domain, Windows use the Simple NTP by default. Clients found within a Windows domain use the secure NTP protocol, also referred to as MS-SNTP, which help in leveraging domain communication, consequently giving an advantage over Authenticated NTP.

Reliable Hardware Clock (RTC)

Windows will not step time unless some conditions are beyond the norm. The implication is that the w32tm changes the frequency at regular intervals while relying on the Clock Update Frequency Settings, which is 1 second on Windows Server 2016.

It will move the frequency if it is behind, and vice versa when it is ahead of time.

This reason explains why you need to have acceptable results during the baseline test. If what you get for the “Computed Time Offset” is not stable, then you may have to verify the status of the firmware.

Troubleshooting Time Accuracy and NTP

The Discovering Hierarchy section gave us an understanding of the source and inaccurate time.

You need to look for time offset to identify the point where the divergence takes place from its NTP Sources. Once you can trace the hierarchy of time, you need to focus on the divergent system to gather more information in determining the issues causing all these inconsistencies.

Here are some tools that you can use:

System event logs

  • Enable logging:

w32tm logs – w32tm /debug /enable /file:C:\Windows\Temp\w32time-test.log /size:10000000 /entries:0-300

w32Time Registry key HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W32Time

  • Local network interfaces
  • Performance counters
  • W32tm /stripchart /computer:UpstreamClockSource
  • PING UpstreamClockSource (gauging latency and understanding the number of hops to source)

Tacert UpstreamClockSource

Problem

Symptoms

Resolution

Local TSC unstable

Use perfmon-Physical computer- Sync clock stable clock

Update firmware or try an alternative hard to confirm that it does display the same issue

Network latency

W32tm stripchart displays the RoundTripDelay exceeding 10ms. Use Tracert to find where the latency thrives

Locate a nearby source clock for time. Install a source clock on the same domain segment or point to one that is geographically closer. Domain environment needs a client with the GtimerServ role.

Unable to reliably reach the NTP source

W32tm /stripchart gives “request time out”

NTP source unresponsive

NTP Source is not responsive

Check Perfmon counters for NTP client Source Count, NTP server outgoing responses, and NTP Server Incoming Requests. Determine the outcome with your baseline tests results

Use server performance counters to determine change in load or if there is any network congestion

Domain Controller not using the most accurate clock

Changes in topology or a recently added master clock

w32tm /resync /rediscover

Clients Clocks are drifting

Time-Service event 36 in System event log or you see a text log with the following description: “NTP Client Time Source Count” going from 1 to 10

Identify errors in the upstream source and query if it may be experiencing performance issues

Baselining Time

Baseline tests are important because they give you an understanding of the expected performance accuracy of the network.

You can use the output to detect problems on your Windows Server 2016 in the future. The first thing to baseline is the root PDC or any machine with the role of GTIMESRV.

Every PDC in the forest should have a baseline test results. Eventually, you need to pick DCs that are critical and get their baseline results too.

It is important to baseline Windows 2016 and 2012 R2 using the w32tm /stripchart as a comparison tool. If you use two similar machines, you can compare their results and make comprehensive analysis.

Using the performance counters, you can collect all information for at least one week to give you enough references when accounting for various network time issues.

If you have more figures for comparison, you’ll gain enough confidence that your time accuracy is stable.

NTP Server Redundancy

A manual NTP server configuration in a non-domain network means that you should have a good redundancy measure to get better accuracy when other components are also stable.

On the other hand, if your topology does not have a good design and other resources are not stable, it’ll lead to poor accuracy levels. Take caution to limit timeservers’ w32time to 10.

Leap Seconds

The climatic and geological activities on planet earth lead to varying rotation periods. In an ideal scenario, the rotation varies every two years by one second.

When the atomic time grows, there will be a correction of a second up or down called the leap second. When doing the correction, it never exceeds 0.9 seconds. The correction is always announced six months before time.

Before Windows Server 2016, the Microsoft Time Service did not account for the leap seconds and relied on external time service to handle the adjustments.

The changes made to Windows Server 2016, Microsoft is working on a suitable solution to handle the leap second.

Secure Time Seeding

W32time in Windows Server 2016 includes the Secure Time Seeding Feature that determines the approximate current time of the outgoing Secure Sockets Layer Connection (SSL). The value helps in correcting gross errors on the local system clock.

You can decide not to use the Secure Time Seeding feature and use the default configurations, instead.

If you intend to disable the feature, use the following steps:

  • Set the UtilizeSSLTimeData registry value to 0 using the command below:

reg add KEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\w32time\Config /v UtilizeSslTimeData /t REG_DWORD /d 0 /f

  • If the machine does not detect any changes and does not ask for a reboot, notify the W32time service about the changes. This will stop enforcing time monitoring based on data coming from the SSL connections.

W32tm.exe /config /update

  • Rebooting the machine activates the settings immediately and directs the machine to stop collecting data from SSL connections.

For the above setting to be effective on the entire domain, set the UtilizeSSLTimeData value in W32time using the Group Policy Setting to 0, and make the setting public.

The moment the setting is picked by a Group Policy Client, the W32time service gets the notification and stops enforcing and monitoring SSL time data.

If the domain has some portable laptops or tablets, you can exclude them from the policy change because when they lose battery power, they will need to re-access the Secure Time Seeding feature to acquire the current time.

Conclusion

The latest developments in the world of Microsoft Windows Server 2016 means that you can now get the most accurate time on your network once you observe some conditions.

The Windows Time Service (W32Time) main work is to give your machine time, regardless of whether it is a standalone or part of a network environment.

The primary use of time in a Windows Server 2016 environment is to make sure that there is enough security for Kerberos authentication.

The W32Time makes it almost impossible to have replay attacks in an Active Directory or when running Virtual Machines on Hyper-V hosts.

Active Directory Authoritative Restore with Windows Server Backup

Overview 

In short lines, an authoritative restore is a Windows Server process of return of a designated deleted Active directory object or container of an object to the state before deletion, at the time when it was backed up. 

An authoritative restore process will replicate the restore object across organization’s domain controllers, but, restore process will increase the Unique Sequence Number (USN) of all attributes on the restored object.  

Because the object will have a much higher Unique Sequence Number, it will replicate across all domain controllers of organization and overwrite anything associated to the previous object. 

In this article, our goal is to describe the procedure and make test example of this process. 

Procedure and Examples 

In an example, hypothetic scenario, it is needed to restore user deleted from Active Directory Users and Computers. 

First thing in the scenario is a restoration from backup. For a backup start, it is needed to restart the domain controller in Directory Recovery Mode (Safe mode). It can be done with a reboot and press key F8 on startup. 

Login is made with local admin, using username.\administrator, and password setter up during domain controller installation for Directory Services Restore Mode ( DSRM ). 

After login, right-click start menu and choose Command Prompt ( Admin ) option. 

When Command Prompt is accessed, following command,  will show available backups:

wbadmin get versions 

Following command (followed by “yes” option ) will start restoration based on the chosen backup entry : 

wbadmin start systemstaterecovery version: (chosen version) 

 And user will be prompted to reboot with “Yes” option. 

After reboot, it is needed to start the Command Prompt (Admin) again, and run ntdsutil command for accessing and managing a Windows Active Directory (AD) database. (Ntdsutil should only be used by experienced administrators and it should be used from an elevated command prompt). 

At ntdsutil prompt, it is needed to enter following commands: 

 activate instance ntds 

And after that : 

authoritative restore 

At authoritative restore prompt terminal, the full path to the object that is wanted to restore should be entered. 

restore object cn=(object name),OU=(organizational unit) ,DC=(domain controller),DC=local 

It is needed to confirm it with “yes”, and restoration will start.  

Exit the authoritative restore with the command:”quit” and ntdsutil with the command: “quit”. 

From Command Prompt terminal, disable safe boot sequence of a server with a command:

bcdedit /deletevalue safeboot 

After reboot and login to the server, a wanted object should be restored in Active Directory. 

Do you want to prevent unauthorized deletion of directory objects or something similar to this problem?

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Windows Server: Clean Up Orphaned Foreign Security Principals

This article will show different ways to clean up orphaned Foreign Security Principals. There are more ways to do it, but before any method described, it is needed to say that if it is possible, clean your “orphaned FSP’s” with GUI method. PowerShell methods are not recommended to users without excellent knowledge of console, due to possible issues that method can cause. 

But first, let’s see overview – What is FSP? 

Overview 

Foreign Security Principals (FSPs) are security principals, created when an object ( user, computer or group) is added to some domain group, but with origins from an external trusted domain. 

FSP is recognized by mark. It is marked with a red curly arrow connected to an icon of object and acts as a pointer. 

Active Directory creates them automatically, after adding security principal from another forest to a group from that domain. 

When security principal, on which FSP is pointing,  is removed, the FSP becomes orphan. Orphan is a term used for FSP’s which have no more principals, FSP is pointing on.   

In the case of the creation of the same principle, old FSP will still be orphaned. New FSP will have different   SID ( security identifier) number, no matter what principle is the same. 

The outcome could be that FSP that is once orphaned, stays orphaned forever until it is removed/cleaned up by the administrator. 

There are two ways of identification and cleaning orphaned FSP. It can be done by GUI ( Graphics User Interface), and by PowerShell console. 

Identification and clean up of orphaned FSP via GUI 

As mentioned before, this is the most recommended way of cleaning orphaned FSP’s. 

In “GUI” way, orphaned FSP can be found in Active Directory Users and Computers console, when advanced features are enabled (If advanced features are not enabled, FSP won’t be seen). They are stored in the ForeignSecurityPrincipals container. Orphaned FSP can be identified through column “Readable Name”. 

If FSP is orphaned, Readable Name column in the console will show up empty. 

They can be cleaned by selection and right-click deletion. 

Cleaning FSP via PowerShell 

For PowerShell cleaning, all FSP objects first have to be listed. 

All FSP’s can be listed by usage of Get-ADObject cmdlet. 

Get-ADObject -Filter {ObjectClass -eq ForeignSecurityPrincipal'} 

When listed, they can be removed by usage of the Translate method, but precaution is advised. There is a possibility, in case of network connectivity issue  FSP’s can be seen as momentarily orphaned, PowerShell method will delete them too, and that can make problems due to SID change.

$ForeignSecurityPrincipalList = Get-ADObject -Filter {ObjectClass eq 
 ‘foreignSecurityPrincipal' }    
foreach($FSP in $ForeignSecurityPrincipalList)  
{      
Try     
 {$null=(New-Object System.Security.Principal.SecurityIdentifier($FSP.objectSid)).Translate([System.Security.Principal.NTAccount])}      
Catch    
  {Remove-ADObject -Identity $FSP}  
} 

Scheduled removal of orphaned FSP 

A task can be scheduled to make removal of orphaned FSP automatic.  

The best way to remove FSP by schedule  is by created script like for example : 

 The fictive company has a monthly turnover of  50 employees. 

A custom script can be made to delete orphaned FSP’s in the time range of 1 month  : 

 

Import-Module -Name OrphanForeignSecurityPrincipals 
$MyCompanyTurnover = 20 
 $OrphanFSPListFilePath ='c:\temp\OFSP.txt' 
$OrphanForeignSecurityPrincipalsList = Get-OrphanForeignSecurityPrincipal TabDelimitedFile $OrphanFSPListFilePath 

If ($OrphanForeignSecurityPrincipalsList) 
 { 
    If ($OrphanForeignSecurityPrincipalsList.Count -gt $MyCompanyTurnover) 
    { 
        $MailParameters = @{ 
            SmtpServer = 'mail.mycompany.com' 
            From       = 'NoReply@mycompany.com' 
            To         = 'Administrator@mycompany.com' 
            Subject    = "Orphan Foreign Security Principals found" 
            Body       = 'Please check attached file.' 
            Attachment = $OrphanFSPListFilePath 
        } 
          Send-MailMessage @MailParameters 
    }    else { 
        Remove-OrphanForeignSecurityPrincipal -TabDelimitedFile $OrphanFSPListFilePath 
    } 
} 

Recovery of deleted FSP 

Deleted orphaned FSP’s can be restored by restoring it from recycle bin if recycle bin feature is activated before deletion is made. 

FSP can be restored via PowerShell cmdlets too : 

An object can be found  with the following cmdlet, and after they are listed, selected orphaned FSP’s can be restored: 

Get-ADObject -Filter 'IsDeleted -eq $TRUE' -IncludeDeletedObjects | Where-Object {$_.DistinguishedName -like "CN=S-*"} 

There is one more way of restoring orphaned Foreign security principals that we need to mention.  

It is the way of following same steps as made before first creation. By adding foreign user/computer/group account into the same groups where it has been before it got orphaned status. This step will create the same Foreign Security principal as it was before, just with different SID number. 

 

Avoid having problems on the FSP or Foreign Security Principals

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How to Configure NFS in Windows Server 2016

NFS  (Network File System) is a client-server filesystem that allows users to access files across a network and handle them as if they are located in a local file directory. It is developed by  Sun Microsystems, Inc, and it is common for Linux/ Unix systems. 

Since Windows Server 2012 R2, it is possible to configure it on Windows Server as a role and use it with Windows or Linux machines as clients. Read to know about How to Configure NFS in Windows Server 2016 here.

How to install NFS to Windows Server 2016 

Installation of NFS (Network File System) role is no different than an installation of any other role. It goes from “Add roles and features Wizard”. 

With few clicks on  “Select server roles” page, under File and Storage Services, and expansion of File and iSCSI Services, the system will show checkbox “Server for NFS”. Installation of that role will enable NFS server. 

The configuration of NFS on Windows Server 2016 

After installation, it is needed to configure role properly. The first stage is choosing or creating a folder for NFS (Network File System) share. 

With right click and properties option, the system will bring the NFS Sharing tab, and Manage NFS sharing button, as part of the tab. 

It will provide  NFS Advanced Sharing dialogue box, with authentication and mapping options, as well as with “Permissions” button. 

Clicking on “Permissions” button will open Type of access drop-down list, with the possibility of root user access, and permission level. 

By default, any client can access the NFS shared folder, but it is possible to control or limit the specific clients, with a clicking of Add button and type the client’s IP address or hostname. 

 Mount NFS Shared Folder on Windows Client 

The steps above make NFS (Network File System) server ready for work.  

To successfully test it, it is needed to mount chosen NFS folder on a Linux or Windows client with following steps: 

  1. It is needed to activate a feature on the client, by clicking Control Panel / Programs and Features / Services for NFS / Client for NFS
  2. After installing the service, it is needed to mount the folder with the following command :
mount –o \\<NFS-Server-IP>\<NFS-Shared-Folder> <Drive Letter>: 

 The command maps folder as drive and assigns chosen letter to it. 

Mount NFS Shared Folder on Linux Client  

No matter NFS is common to Linux / Unix systems, it is still needed to mount folder to a system via command, similar to windows systems. 

mount –t NFS <NFS-Server-IP>/<NFS-Shared-Folder> /<Mount-Point> 

 

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Overview: How to Troubleshoot Active Directory Replication Issues

Active Directory Replication is more or less the center of all sorts of problems. It is a crucial service and it becomes more complicated when dealing with more than one domain controller.  Issues relating to replication can vary from authentication issues and problems arising when trying to access resources over the network. 

All objects in the Active Directory are replicated between domain controllers so that all partitions are synchronized. A large company with multiple sites means that replication takes place at the local site as well as the other sites to keep all partitions synchronized. This article aims to show you how to troubleshoot Active Directory replication issues. 

Active Directory replication problems come from different sources, some of which are Domain Name System failures, network problems, or security issues. 

Resources Needed to Troubleshoot Active Directory Replication 

Failures coming in and out the active directories due to replication issues lead to many inconsistencies between domain controllers. Such failures lead to systemic failures or inconsistent output. Identifying the main cause of replication failure helps system administrators identify the possible cause and hence elimination of the problem.  One of the commonly used interfaces based replication-monitoring tool is the Active Directory Replication Status Tool. 

Understanding Recommendations from the tool solution 

The red and yellow warning events in the system logs will always point out to the specific cause of replication failure and give the source and destination in the Active Directory. Any steps that are suggested by the warnings should be tried as explained. Other tools such as the Repadmin tool can give more information to help resolve replication issues. 

  • Eliminating Disruptions or Hardware Failures 

Before troubleshooting replication failures, it is important to rule out any issues related to software updates or upgrades, intentional disruptions, software configurations, and hardware failures. 

  • Intentional Disruptions 

Disruptions caused by unavailability (offline state) of a remote domain controller can be corrected by adding the computer as a member server using the Install From Media (IFM) method to configure the Active Directory Domain Services. The Ntdsutil command-line tool can be used to create installation media. 

  • Software Upgrades and Hardware Failures 

Hardware failures can come from failing motherboards or hard drives. Once a hardware problem is identified, system administrators should take immediate action to replace the failing components. Active Directory Replication failures can take place after a planned upgrade. The best way to handle this is through an effective communication plan that prepares people in advance. 

  • Software Configurations 

Some software settings such as the typical windows firewall have port 135 open alongside other advanced security settings. Some firewalls can be configured to allow for replication. 

Responding to Failures Reported on Windows 2000 Server 

Active Directory configured on Windows 2000 Server that has failed beyond the tombstone lifetime should be resolved by: 

  • Moving the server from a corporate to a private network 
  • Removing the Active Directory or Reinstalling the Operating System 
  • Removing its metadata from the Active Directory to hide its objects 

Removing the server metadata ensures that any attempt by the server to revive objects settings after 14 days is impossible. This also helps avert further error logs due to replication attempts with a missing Domain Controller. 

What are the Root Causes of Replication? 

Apart from the already discussed causes leading to replication failures, here are some other reasons. 

Network Connectivity: caused by unavailable network or wrong configurations 

Name Resolutions: Wrong DNS configurations 

Authentication and Authorizations: Aces denied errors every time a domain controller tries to connect for replication 

Directory Database: A slow data store not being able to handle fast transactions that take place within replication timeouts. 

Replication Engine: when replication schedules are short, it will lead to longer queues and large processing which may not be possible within the outbound replication schedule. 

Replication Topology: All domain controllers need to have links linking them to other sites within the Active Directory.  The links should map wide area networks or the virtual private network connections. All objects should be supported by the same site topology within the network to avoid replication failures. 

How do We Fix Replication Problems 

Any of the following approaches can be used to fix Active Directory Replication Issues: 

  • Daily monitoring of the state of replication using the Repadmin.exe to extract daily status updates 
  • Resolving reported replication failures as soon as possible, using steps provided in the event logs. Replication failures resulting from software configurations require un-installation of the software before attempting any other solutions. 
  • If all attempts to resolve replication issues do not work, remove the Active Directory Directory Services from the server and reinstall. 

When an attempt to remove AD DS fails when the server is online, any of the following methods can resolve the issue. 

  • Force the removal of the AD DS from the Directory Restore Mode (DSRM) by cleaning up the server metadata and reinstall the AD DS. 
  • Reinstall Operating system and reconfigure the Domain Controller 

Retrieving Replication Status Using Repadmin 

When everything in the Active Directory is working as intended and produces no errors, then it means the following services are working correctly: 

  • DNS 
  • Remote Procedure Call (RPC) 
  • Network Connectivity 
  • Window Time Service (W32time) 
  • Kerberos Authentication Protocol 

The Repadmin tool is used to study the daily replication activities. The tool is able to access all the replication status of all domain controllers in the forest. The report is relayed in a .CSV format that can be accessed using any spreadsheet reader. 

Generating Repadmin for Domain Controllers in a Spreadsheet.                                 

Using the command prompt as an administrator type the following: 

Repadmin /showrepl * /csv &gt; showrepl.csv 

  • Open Microsoft Excel, navigate to the showrepl.csv, and click open 
  • Hide or delete column A and the Transport Type Column 
  • Select the row below the column heading and click freeze panes by clicking on Freeze Top Row 
  • Select the whole spreadsheet and click filter from the data tab 
  • Click on the down arrow below the source DC column, point to text filters, and select the custom filter. 
  • In the custom AutoFilter box, below show rows where click on does not contain.  On the box next to it, type Del to eliminate results from deleted domain controllers. 
  • Repeat the previous step for the Last Failure Known Column and use does not equal and type 0 
  • Resolve replication issues. 

 Conclusion 

Replication going on smoothly throughout the Active Directory is critical. Poor replication means all manner of problems from authentication to inconsistent results.  The article is supposed to help you check on your system’s replication status and learn how to resolve the common replication errors.  

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Guide for Securing File Server

How hardened is your organization’s file server to protect data from unauthorized access? Every organization running a file server needs to have a way of protecting sensitive information from unauthorized access, especially from outside.

The fact that your server may be in a physically secure place does not mean the security configurations within the operating system should be ignored and the system left at the mercy of anyone with an access to the building.

The file server being the most visible and central network device with critical information should be secured using some of the approaches this guide proposes. System administrators should use the hacker’s point of view when reviewing security policies to help them find a better approach to server security settings.

The Guide

Securing a file server ensures that the organization enjoys the fill benefits of a server in its opium working condition. Here are some of the steps one needed to enforce server security settings.

1. The configuration of the operator group
Instead of using the default Administrators group, another group of people (user accounts) authorized to access the server using different access levels should be created. The default administrator account should be used as the final resort.

Operator Group can be defined by different tasks users are assigned as far as modifications of security settings are concerned. To perform this task, open the Organizational Unit and remove unwanted groups, but retain the default Domain Administrators. Create the Operators Group and give Full Control to both Domain Administrators and Operators group.

2. Create A Security Template
By the time you sit down to secure the File Server, you must already be having security settings that can be used on the network or in a standalone environment. Security setting templates can be created and then be imported into group policy to be implemented across the entire network.

The security templates need to be flexible in that when more than one is applied to the same server, there should never be a conflict.

Setting Account Policies
Account policies are settings that have to do with Passwords, Account Lockout, and Kerberos Policy. All policies should be applied at the domain level. For a standalone file server, the local accounts are used to access it, therefore security settings of these accounts need to be set up.

Other settings include:

  • Increasing the minimum password length – long passwords mean that the hacker longer time to crack local account passwords.
  • Decreasing maximum password age – reducing the aging date of a password means more frequent password changes, therefore, increasing the integrity of local user accounts.
  • Account lockout duration – this setting determines the lockout period a person has to wait to re-enter the password. A ‘0’ setting means the user logged out until password reset and a ’30’ means attackers will have to wait longer to key in more attempts.

Setting the Local Policies
Under local policies, system administrators need to look at the Audit policies, user rights, and security options.

  • Audit Policy
    Turing on the Audit Policy setting is an indication that the files, registry, folders, and printers can be tracked. This gives the administrators the freedom to choose which objects to log and the level of monitoring to use. In a high-security environment, knowing who is responsible for what activity is paramount, therefore auditing privileges is required when securing the File Server.
  • User Rights
    When setting user properties on a local machine, rights such as “Act as part of the operating system” should be disabled.
  • Security Options
    Some default settings under this option can be used to tighten the security levels of a file server. Some of these defaults may not work with all Server Operating Systems, therefore testing before implementation is recommended.

Settings on Services
Services not installed should be disabled and a person responsible for starting, stopping, and disabling them identified. There are two specific services that can be applied in specific scenarios: Distributed File System (DFS) and File Replication Service (NTRFS).

The DFS works on local disks, shared across networks, therefore in such a scenario, disabling DFS means that users must know the names of the shared resources and servers on the network. NTRFS controls the automatic maintenance of files across multiple servers and it must be on Active Directory and Domain Controllers.

3. Determine the Template Application Strategy
Security templates can be imported to Group Policies and the domain so that they can be shared across multiple workstations and can be refreshed as needed. When dealing with workstations, security policies can be set using the /secedit/ command and the batch files re-written to refresh the settings.

4. Set up Restricted Groups
Make use of the Local Group Policy to restrict group activities. Local Administrators and any group that was created can be restricted. New users can be added to the restricted groups. Restricting administrators who can change system settings prevents unauthorized access.

5. Write IPsec Policies
Setting IPsec rules that block certain or all ports by applying specific filters to allow only communication from specific computers will guarantee File Server security. When left open, File Servers share information through various protocols that would-be attackers will find useful.

6. Set the Correct System
The correct time is critical for many reasons. Some authentication protocols need the client and server clocks to be synchronized. Synchronizing events between computers on a network will not take place due to time differences. When reading logs, the time stamp is important for auditing purposes.

7. Set Specific Account Restrictions
Restrictions can be implemented on individual accounts by limiting the hours, restricting which workstation a particular user an use, prevent account delegation, etc.

8. Setting the Local Server Security Settings
Settings that cannot be automated in a domain such as Guest user account and Guest group have unique identifiers that make it difficult to have an automated security setting. In such scenarios, setting local policies is necessary.

9. Track Attack Indicators
Events with warnings such as ‘Logon Failure’ and an increasing number of similar events should be treated as unauthorized attempts.

10. Using the Network File System (NTFS)
Setting the Access Control List (ACL) and the System Access Control List (SACL) on FAT volumes is not possible. File Server security depends on its ability to have security settings done as file permissions.

11. Use of Administrative Template Settings
Some security settings are not available in security template settings. They can only be set via the Administrative Templates within the Group Policy. Disabling error reporting at this stage is recommended because some error logs contain sensitive information that can be intercepted by hackers.

12. Documenting and Maintaining the Security Settings
When server security settings need to be altered, previous settings can be used as a reference point. Third-party tools such as Security Configuration Analysis can be used to verify the compliance of the security settings in place.

Conclusion

The security settings above are supposed to make the File Server secure. However, when doing so, make sure the settings do not interfere with server’s normal operations. Since every network setup is unique, it is recommended that File Server security setting is set up according to the needs and expectation of the organization.

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Windows Server Optimization: Active Directory Auditing – Track User Logons

Tracking user logons gives system administrators an opportunity to identify active and inactive accounts and global access rights that could put the organization information at risk.

Active Directory auditing involves the collection of data on all Active Directory Objects and attributes that are helpful in analyzing and reporting the overall health of the Active Directory.

Audits are performed to secure the Active Directory from attacks and to keep the IT operations running. Tracking User Logons is needed to help in the following operations:

1. Track the logon activity on Domain Controllers.
2. Track user logon activities (logon failures, recent logons, last logon on workstations).
3. Track logon activities on Member Servers and Workstations.
4. Monitor RADIUS logon on computers.

In a busy working environment, Active Directory Auditing helps verify the number of users accessing the Active Directory at any given time, identify remote logon users, determine the peak logon sessions, monitor all critical logons, act on unauthorized attempts and access, and generate backup reports in case of any queries or investigations.

Why Using the Native Active Directory Auditing is Insufficient

1. The day-to-day logon information collected in the server logs may not be friendly to non-technical staff.
2. The logon information requires expertise to understand the specific events correlating to every logon activity.
3. The amount of data collected is voluminous due to the continuous activities on the Domain Controller. Dealing with such huge amount of data is tedious and time consuming.
4. The restrictive nature of the Domain Controllers means access to its logos are limited to specific personnel.
5. The inability of other Non-Administrative staff outside the IT department to access real time logon data also makes the Native Active Directory Auditing out of reach for managers, auditors, human resource staff, etc.

The Solution to Native Active Directory Auditing

The only possible way of tracking real time logon activities on a large scale for auditing is to use a software like Manage Engine ADAudit Plus that details all logon information into a single document that can be shared from a central server console.

The ADAudit Plus tool gives all information relating to successful and failed logon attempts.

Active Directory Logon Auditing

Real time auditing means tracking every logon activity as it happens to the entire Active Directory. The outcome of this audit is listing all logon activities that can be viewed on the central server in an instant.

The logon report contains information on failed logons, Domain Controller logon information, Member Server logon information, Workstation logon, recent and last logon activities.

Active Directory Logon Auditing also helps in reporting on specific logon events by listing all Logon related actions. All this information is presented on a web interface displaying data in statistical format via charts, lists, and graphs. Due to the insufficient nature of Active Directory, using the ADAudit Plus relays more information some of which are explained below:

Logon Activities on Domain Controllers
Domain Controllers from the critical element in Active Directory because all changes taking place in the Active Directory takes place here. Such logons are restricted to network administrators or privileged users. Any attempts by other users should be a wake up call for administrators to take corrective action.

ADAudit Plus give details such as user’s location, time of logon, success or failed logon attempts, and the reason for failure if any.

Tracker User Logon Activities (logon failures, recent logons, last logon on workstations)
Logon failure report gives information on reasons why a failure occurred and the number of failed attempts reported for a particular user. This information could be useful for system administrators on possible external attacks.

Some common reasons for logon attempts could be related to bad name or wrong password. Other reasons such as errors due to time restrictions, replication delays, and different workstation OS version can also be reported.

Reports on user logon give all the information needed for auditing the entire logon history on the server and the clients end. This information is only accessible to specific domain users. User’s logon history is used to draw a logon pattern and used to show system auditors proof of activities on the network.

Recent activities are used by administrators to ascertain whether every past logon was used as intended. An analysis of past logon can be used to measure levels of irregularities. ADAudit Plus gives details of both successful and failed logons alongside reasons for unsuccessful attempts. The unsuccessful logs are used for planning any corrective measures.

The last logon on workstations has all the information on the time of last successful logon attempts. The report of this audit can be used to show absenteeism or availability of a user.

Track Logon Activities on Member Servers and Workstations
Tracking logon activities on member servers and workstations help administrators tracks the logon activities of users with authority to access selected servers and workstations. The type of information displayed here are times of access, location of the user, including the workstation details, successful or failed logins, and the reason behind the logon failure.

Monitor RADIUS Logon on Computers
Users accessing the Domain server from a remote location need to use the Remote Authentication Dial-in User Service (RADIUS). Getting reports on remote users in the form of logon failures, authentication through the Active Directory and logon history. Only RADIUS logon activities running through Network Policy Servers can be reported.

Conclusion

Since the aim of any server optimization is to speed up operations and in the case of logon auditing, speed up reporting. Native Active Directory Auditing may give comprehensive information, but is weighed down by the reporting time.

System administrators should take advantage of Active Directory auditing tools such as ADAudit Plus to help in carrying Active Directory audit. An Active Directory Reporting tool should be able to filter out information by marking out WHEN a change in the Active Directory was made, WHERE the change took place, WHAT is the nature of the change, and WHO is responsible for the change.

All these identifiers in a report are to facilitate easier understanding when reviewing the summarized information.

 

 

 

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How to Migrate Filesystems Data to Windows Server 2016

One of the most difficult and time-consuming tasks for IT Administrators is migrating file shares and their permissions. Before embarking on the migration, some procedures need to be followed to avoid mishaps like broken file systems or lost files.

The most common form of data migration is done by carrying all files and permissions. Microsoft has an inbuilt tool and PowerShell commands used as the migration tools. The migration utility eases the migration process by moving several roles, features, and even the operating system to a new server.

Depending on the prevailing circumstances prompting the migration we need to answer questions like:

1. Are we preserving the existing domain?
2. What are the settings of the old server?
3. Was the server running on a virtual machine?
4. Was the virtual machine on a different platform from the one we are moving files into?

Regardless of the reason behind the migration, different methods can be used to initiate the migration. If the existing server system has some pending issues, you are advised to sort them out before starting the migration process.

Using the Windows Server Migration Tool

We need to install the migration tool to ease the migration process. The Microsoft Server Migration tool will transfer server roles, feature, and some operating system to the destination server.

1. To get started, you need to install the migration tool through the PowerShell console using the following command:
Install-WindowsFeature –ServerName DestinationServer

2. Create a deployment folder on the destination server using the smidgeploy.exe utility (it is installed as an additional utility by the above command). To specify some specific attributes, use the following command:
C:\Windows\System32\ServerMigrationTools\SmigDeploy.exe /package /architecture amd64 /os WS08R2 /path <deployment folder path>

3. Create a deployment folder on the destination server, and then transfer its contents to the old server.

4. Use the Remote Desktop Protocol (RDP) to connect to the old server and run the smidgeploy.exe usually found on the following path:
C:\<DeploymentFolder>\SMT_<OS>_<Architecture>

5. After the installation, enable the destination server to accept deployment data. This is done using the PowerShell console using the following command:
Add-PsSnapin microsoft.windows.servermanager.migration

The PSSnapin command will activate all the PowerShell cmdlets.

6. Run the Receive-SmigServerData to open connection to the destination server. The time it takes to open connection is less than five minutes.

Sending Data to the Destination Server

1. Use the Send-SmigServerData in the PowerShell console. The following command defines the source path (remember the deployment folder that was copied from the destination server):
Send-SmigServerData -ComputerName <DestinationServer> -SourcePath <SourceDeploymentFolder> -DestinationPath <DestinationDeploymentFolder> -Include All –Recurse

2. When prompted for the password, use the password that was issued when running the Receive-SmigServerData on the destination server.

3. When the command completes, all file properties should be transferred to the destination server.

TIP: Confirm that all shares were transferred successfully by using Get-SmbShare in the PowerShell.

Alternatives to Windows Server Migration Tools

This involves taking the most recent backups and restores them on the new server. The backup method restores the data and not the file system. All the file permissions on the new server will be the same as before when they were on the old server. This is a generally fast approach, but the speed depends on file sizes.

1. Using the Free Disk2VHD Tool
If the current server is not virtualized, the Disk2VHD utility from Microsoft is reliable and fast because the subsystem allows the storage of files regardless of their sizes.

All NTFS permissions are retained and transferred to the new drive. The advantage of using this tool is the automatic creation of a fully compatible Hyper-V virtual drive.

2. Copy Utilities
Microsoft has many built-in coper utilities that transfer files with all permissions. The common server migration copy utilities are the XCOPY and ROBOCOPY.

Using XCOPY
The typical command should look like this:
XCOPY “\\sourceServer\ShareName\*.*” “\\destServer\ShareName\” /E /C /H /X /K /I /V /Y >Copy.log 2>CopyErr.Log

The parameters taken by the commander are:

/E – Copies both empty and directories with content.
/C – Copies without acknowledging errors.
/H – Copies all hidden and system files.
/X – Copies file audit settings (implies /O).
/K – Copies attributes; without this attribute will reset read-only attributes.
/I – Creates a directory if the file destination does not exist.
/V – Verifies the size of each new file.
/Y – Suppresses the prompt asking to overwrite existing destination file.

The command will execute and leave the output to a file and a corresponding error log file.

Using ROBOCOPY
The Robocopy command looks similar to this:
ROBOCOPY “\\sourceserver\ShareName” “\\destServer\ShareName” /E /COPYALL /R:0 /LOG:Copy.log /V /NP

The parameters taken by the command are:

/E – Copy all directories and its subdirectories.
/COPYALL – COPY ALL file info.
/R:0 – Number of Retries on failed copies: default 1 million. (When set to 0 it disables retries so that copy can go on uninterrupted.)
/LOG – Output the LOG file status.
/V – Produce output in details.
/NP – No Progress – Copy without displaying the percentage of files copied.

3. File Synchronization or Replication
Microsoft has many inbuilt tools that help system Administrators replicate data between two servers. This is disaster preparedness plan done to ensure data is available at all times.

The Distributed File System Replication (DSFR) is one way of synchronizing the contents between two shares. They can work with the Distributed File Name Space. Using the DFSR enables user shares via the path: \\Domain\share and not \\server\share

Both the DFSR and the DFS can bring together more than two servers to use one share pointing to multiple servers. Using the DFSR is easy when it comes to adding another server on an existing migration configuration.

Shares and Permissions

Since Windows 2000, file shares are stored in the registry at:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\LanmanServer\Shares

Instead of recreating shares, you can export this key to get all your drive paths and permission used by define shares. Using the registry to export shares means that all drive letters in the new server must match with the old server paths. To avoid any confusion, you are advised to assign same drive letters on both servers.

Conclusion

Whichever way you choose to migrate filesystems should be the most convenient and comfortable for you. All this depends on the level of skill and time needed to reduce the downtime likely to affect server operations.

Admin’s Advice: No to ‘Deny’ Permission

In this article, we will bring you some solutions that can help resolve an incorrect grant of a User’s rights. These solutions may also make an Administrator’s life easier by dealing with the consequences brought about by the misuse of the “Deny” permission.

Take this scenario as an example. The user changed Folder Permissions to Deny everyone. The Administrator then reverted these changes. It may appear that the situation has been fixed but the permissions show that the reverting of the settings is meaningless. Everyone still got the permission to read and write in the aforementioned folder. For an Administrator, the first step for this scenario is to check the perspective of Sharing and Security on a top-level folder. In our scenario, the sharing is set as follows: Domain Users, Administrators, and Domain Admins have read/write permissions; NTFS is set to give full control to System, Domain Users, and Domain Admins. The subfolders, meanwhile, have inheritance disabled since each subfolder has its own set permissions.

As we can see, the system in our imaginary scenario is a mess. But don’t lose hope yet, the situation can still be fixed. In fact, there is more than one solution that can fix the issue.

Before we go deeper into the solutions, the Administrator should keep in mind that ‘Everyone’ applies to all users, whether they are logged in or not. It also applies to those on or off the domain.

Let’s clarify some terms first. Authenticated Users are users that logged in the domain or forest. Domain Users are those that are on the current server’s domain. Make sure to keep this in mind because a ‘Deny’ on any of these may also mean a ‘Deny’ on the Administrator!

SOLUTIONS

Solution 1 – All users can log off then log back in again. This action enforces new NTFS permissions to the folder. If not all Users can log off simultaneously, the new settings can be set to standby until they do.

Solution 2 – Backups can be used to roll out the old settings and revert the permissions to the way they were before. Keep in mind that performing a Backup may take time so it is not recommended to do this during work hours, or if there are Users logged on to the system.

Solution 3 – The Administrator can get some insights into the User Permissions by clicking ‘Advanced’ in the Permissions window and then going to the Effective Access Tab. The Users and their individual access is shown in this tab. Although not an exact solutions, the Administrator can find answers to what permissions are set and being used.

Solution 4 – The easier solution is to crate new folders with the correct permissions applied to it and make these servings apply to the current folder and all the subfolders and files. Once all this is set, everything can then be moved to the folder with the corrected permissions. The Administrator has the option to take full ownership, rewrite permissions, and give full access to Domain Admins. After that, it is possible to decide who can have read/write permissions.

The administrator can give Authenticated Users Read/Write permissions and they can be used to handle access with shared files and folders at the NTFS level. This is a better situation that trying to limit access to sharing at the Share Access Control Layer. Using ’Deny’ permission is always the worst and last solution as it has a broad scope and it denies ‘Everyone’ by default.