DNS Zone Types Explained, and their Significance in Active Directory

Posted on April 30, 2013 by Ace Fekay

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Ace Fekay, MCT, MVP, MCSE 2012/Cloud, MCITP EA, MCTS Windows 2008/R2, Exchange 2007 & 2010, Exchange 2010 Enterprise Administrator, MCSE 2003/2000, MCSA Messaging 2003
   Microsoft Certified Trainer
   Microsoft MVP: Directory Services
   Active Directory, Exchange and Windows Infrastructure Engineer and Janitor

Revisions

Original publication 4/30/2013

Prelude

Ace here again. I thought to touch base on DNS zones, and more so, focus on what AD integrated zones are and how they work. This blog almost mimics my class lecture on this topic. Check back for updates periodically, which I will notate with a timestamp above with whatever I’ve added or modified.

This topic was also briefly discussed in the following Microsoft Technet forum thread:
Technet thread: “Secondary Zones?”
http://social.technet.microsoft.com/Forums/en-US/winserverNIS/thread/c1b0f3ac-c8af-4f4e-a5bc-23d034c85400

AD Integrated Zones AD Database Storage Locations

First up is a background on the various parts of the Active Directory database and what gets stored in them. This will help understand where DNS data is stored as I discuss it later in this blog.

The Active Directory Data Store (the AD database):

There are three possible storage locations for DNS zone storage in the Active Directory database:

DomainNC – This was the only available location with Windows 2000. This replicates to all DCs only in a specific domain.
DomainDnsZones partition – Introduced in Windows 2003 and used in all newer operating systems. This replicates to all DCs only in a specific domain in the forest.
ForestDnsZones partition. This replicates to all DCs in the forest.

You can see how not all partitions are replicated forest wide. It depends on the partition:

Ok, Now the DNS Basics:

A Secondary is a read-only copy
A Secondary zone stores it’s data in a text file (by default in the system32\dns folder)
A Secondary gets a copy of the zone data from the Primary
A Primary is the writeable copy
A Primary stores it’s zone data in a text file (by default in the system32\dns folder)
There can only be one Primary, but as many Secondary zones as you want.
You must allow zone transfer capabilities from the Primary zone if you want to create a Secondary.
AD integrated zones do NOT need zone transfers to be allowed (see below for specifics)

Active directory Integrated Zones changes this a bit:

AD Integrated zones are similar to Primary zones, however their data is stored as binary data in the actual AD database and not as a text file. The specific place in the AD database depends on the DC’s operating system version and replication scope, which means what “logical” part of the physical AD database it’s stored in, which will affect which DCs in the forest it will replicate to.

The “only one Primary Zone” rule is changed by introducing the Multi-Master Primary feature. This is because the data is not stored as a text file, rather it is stored in the actual, physical AD database (in one of 3 difference logical locations or what we call the Replication Scope), and any DC that has DNS installed (based on the replication scope) will be a writeable copy.
The zone data is replicated to other DCs in the replication scope where the data is stored (based on one of the 3 logical locations)
Each DC in the replication scope that has DNS installed, will automatically make available the zone data in DNS
Each DC that hosts the zone can “write” to the zone, and the changes get replicated to other DCs in the replication scope of the zone/
The DC that makes a change becomes the SOA at that point in time, until another DC makes a change to the zone, then it becomes the SOA
An AD Integrated zone can be configured to allow zone transfers to a Secondary, but the Secondary CANNOT be a DC in the same replication scope as the zone you are trying to create as a Secondary, otherwise the DC you are attempting to create the Secondary on will automatically change it to AD integrated, since it “sees” it in the AD database. In some cases, if this is forced or done incorrectly, it can lead to duplicate or conflicting zones in the AD database, which is problematic until fixed.

And if you install DNS on another DC, the zone data will *automatically* appear because DNS will recognize the data in the AD database. AD integrated zones can also act as a Primary zone for secondary zones, whether they are on Windows machines, BIND (on Unix) or any other name brand.

Remember, AD integrated zones still follow the RFCs, but have more features.

Duplicate or Conflicting zones?

Since I touched based on duplicate and conflicting zones, you may want to check if they exist in your AD database. You have to check each partition, and if you have more than one domain, you have to check the DomainDnsZones and DomainNC of each domain. You may even have to check it on multiple DCs in various AD Sites to see if they all “see” the same copy or different copies. You would be surprised what I’ve seen with AD replication problems and seeing different DCs “seeing” something different in its own database. This issue also manifests as a symptom in more than just a DNS problem, where you create a user on one DC and it never replicates to another DC.

Using ADSI Edit to Resolve Conflicting or Duplicate AD Integrated DNS zones
http://msmvps.com/blogs/acefekay/archive/2009/09/02/using-adsi-edit-to-resolve-conflicting-or-duplicate-ad-integrated-dns-zones.aspx

Primary Standard Zone, Secondary Standard Zones & Zone Transfers

Zone transfers allow you to create a read only copy (a Secondary zone) on another DNS server, that will pull a copy (transfers) from the read/writable zone (the Primary zone).

Primary and Secondary zones store their data as text files.

On a Windows machine, the zone files can be found in the \system32\dns folder with a file name such as “domain.com.dns”. You can have numerous read only copies, but there can only be one read/write of that zone.

Please keep in mind, the authoritative DNS server listed in the registrar for a public domain name (zone) does not have to be a Primary, it’s just the host nameserver listed as authoritative. It can get it’s data from a Primary that is not listed, hence the writable copy is actually hidden and protected from public access.

Do I need Zone transfers Allowed for AD Integrated Zones if I do not have Secondaries Zones?

The short answer: NOPE.

The reason is that the term “AD Integrated” means the zone is stored in the AD database, and the zone will replicate to other domain controllers within the same replication scope (domain-wide or forest-wide) automatically as part of the AD replication process.

By default, AD integrated zones are configured to not allow zone transfers.

Allowing zone transfers is an option provided to support non-DC DNS servers, BIND or any other name brand DNS server that you want to allow zone transfers to a secondary on those servers.

Rotating SOA

Additional security options of AD integrated zones, is one of the feature of AD integrated zones, as well as the fact that there can be more than one Primary zone copy of it. This is because all DNS servers that host the zone in a domain or forest has the ability to be a writable copies and becomes the actual “start of authority” (SOA) of that zone when a specific DC/DNS accepts a write operation, such as a client machine registering, or the DC itself updating its SRV records.

For example, if a DC updates it’s SRV and other records at the default 60 minute interval (all other machines register every 24 hours), it will update its data into the DNS server listed as the first DNS address in the network card. This server now writes it into DNS and NOW becomes the SOA of the zone. That data is replicated to other DC/DNS servers with default AD replication. Now all other DC/DNS servers will see the change.

To further explain, since the zone is AD integrated, each and every DC in the replication scope of the zone, can accept changes, due to an AD integrated zone’s Multi-Master Primary Zone features. Based on the definition of what an SOA is, that is being the DNS server that’s authoritative to accept writes, therefore, whichever DC/DNS accepted a change to the zone, that specific DC/DNS will become the SOA for that moment in time. Then when the next DC/DNS that accepts a change, it will now become the new SOA. The SOA constantly changing in an AD environment is accepted, and default behavior.

That is why you can watch the SOA name on AD integrated zones change. The data is replicated automatically as part of the AD replication process because it is stored in the AD database.

Active Directory-integrated DNS zone serial number behavior (SOA default behavior)
http://support.microsoft.com/kb/282826

References

Configure AD Integrated Zones
(When converting to AD integrated zones)
Quoted: “Only primary zones can be stored in the directory. If a zone is configured on other domain controllers as a secondary zone, these zones will be converted to primary zones when you convert the zone to AD integrated. This is because the multimaster replication model of Active Directory removes the need for secondary zones when a zone is stored in Active Directory. Conversion of the zone from secondary to primary will occur when AD DS is restarted.”
http://technet.microsoft.com/en-us/library/ee649181(v=ws.10)

Understanding DNS Zones
http://www.tech-faq.com/understanding-dns-zones.html

Understanding stub zones: Domain Name System(DNS)
Jan 21, 2005 – The master servers for a stub zone are one or more DNS servers authoritative for the child zone, usually the DNS server hosting the primary …
http://technet.microsoft.com/en-us/library/cc779197(v=ws.10).aspx

Reanimate an Exchange Server Deleted From the Exchange Organization in the Configuration Container in Active Directory

Posted on April 19, 2013 by Ace Fekay

By Ace Fekay
MCT, MVP, MCSE 2012/Cloud, MCITP EA, MCTS Windows 2008/R2, Exchange 2007 & 2010, Exchange 2010 Enterprise Administrator, MCSE 2003/2000, MCSA Messaging 2003
Microsoft Certified Trainer
Microsoft MVP: Directory Services
Active Directory, Exchange and Windows Infrastructure Engineer & Janitor

Background:

Hey everyone, Ace here again. Here’s an interesting issue I came across when an administrator, while using ADSI Edit, deleted one of their Exchange 2010 servers from the Exchange Organization in AD’s Configuration Container. Of course, it was not intentional, so I didn’t even ask why or how, but I was told that they were working on something else in ADSI Edit, and the administrator unintentionally deleted the Exchange server object. And as we all know, there is no “Undelete” button in ADSI Edit.

Before I went about trying to perform an Authoritative Restore with AD, I figured I would try to use the AD Recycle Bin to recover the object. However, I knew it wouldn’t be there, because it was never deleted from ADUC Computer Container, rather it was deleted from the Exchange Organization. But I did it just to show how to do it, and to illustrate the differences in the object’s locations and significance.

What I did was is re-animated the deleted server using ADSI Edit. I used a lab machine to test it before attempted to try it on their production system.

Before I performed a test delete in my lab

Here are the three Exchange Servers, Van-EX1, Van-EX2, and Van-EX3, showing in the ADUC’s Computers Container:

Here’s VAN-EX3 in ADSI Edit and its attributes. This is what it’s supposed to look like.

Looking further into the server object attributes in ADUC Advanced View, Attribute Editor, it shows the server’s ObjectSID:

Delete VAN-EX3

Here’s where I deleted VAN-EX3 in ADSI Edit:

The delete warning message:

And the second delete warning message. Apparently ADSI Edit, the tool that doesn’t have an Undelete” button, wants to make sure that you want to delete it. I think it’s good that it asks twice:

VAN-EX3 has now been deleted from the Exchange Organization section in the Configuration Container:

However, as you an see in ADUC, it still shows VAN-EX3. That’s because we didn’t delete it from AD, rather it was deleted from the Configuration Container.

As you can see here, Exchange’s services still show that they’re still running.

Trying to find the deleted object in the Recycle Bin using LDP

Here’s where I looked for the Exchange object in the Recycle Bin using LDP. However, since the Exchange computer object still exists in AD, rather it was deleted from the Organization. I knew it won’t be in the Recycle Bin, because it wasn’t really deleted from AD.

These steps were more to show everyone the differences between a deleted computer object, that would show up here, and an Exchange server deleted from the Organization.

Click Connection, then Bind:

We’re binding using default values, meaning it will use the currently logged on domain administrator account.

In LDP, click Options, then Controls:

In the Load Predefined drop-down box, I chose to “Return Deleted Objects:”

As you can see, Return Deleted Objects chosen in the drop-down box:

Under Tree View, for the base DN, I typed in cn=deleted objects,dc=adatum,dc-com. As you can see, nothing showed up. So VAN-EX3 is not in the Recycle Bin.

Recreating VAN-EX3 in the Exchange Organization in the Configuration Container

I drilled down into the Exchange Organization in the Configuration Container, CN=Exchange Administrative Group (FYDIBOHF23SPDLT), CN=Servers. Then I right-clicked CN=Servers, New, Object.

By the way, not to get off topic, but if you’re wondering how the Exchange team came up with that Administrative Group name, “(FYDIBOHF23SPDLT),” click here.

Once the server object has been created, now we need to create the necessary Exchange server object containers under the server object we created. What helps is that the attributes are still in AD:

For “Select a Class” dialog box, scroll down and select msExchServersContainer

For the Value field, type in VAN-EX3:

Click Finish:

Now we must create the Exchange Information Store container. Right-click, New, choose Object:

In the Select a Class dialog box, choose msExchInformationStore:

Type “Information Store” in the Value field:

Click Finish:

The values appear correct so far. If you double-click on the CN=Information Store object, scroll down, you can see the DN value is correct (sorry, I didn’t screenshot that part):

Now let’s create the MTA. Same deal as above, in the Select a Class dialog box, right-click, New, scroll down and choose mTA:

Type in Microsoft MTA:

To get the time out and other values it’s asking, I opened another instance of ADSI Edit, and looked at the values for one of the other existing Exchange Servers:

The transRetryMins value of 5 that I populated, which I found from the other Exchange server:

The last attribute, which of course is the server’s name:

Now we must create the Microsoft System Attendant object for VAN-EX3 by right-clicking Van-Ex3, new, choose Object, and in the Select a Class dialog box, scroll down and select exchangeAdminService:

For the CN value, type in Microsoft System Attendant:

Scroll down in the Attribute Editor to deliveryMechanism, set it to 0 (zero):

Click Finish:

Now test logging on with a mailbox that exists in VAN-EX3, and try to send and receive an email. You should find that it works perfectly.

Point of the story: Be careful what you do in ADSI Edit.

Suggestions, Comments, Corrections are welcomed.

Ace Fekay

Redirect OWA Exchange 2010 & Exchange 2013 – The Cool and Easy Method

Posted on April 16, 2013 by Ace Fekay

Preface

Hey everyone, Ace here again. An issue was presented to me regarding the EMC and EMS would not open on a new Exchange 2010 SP3 installation. The underlying operating system is Windows 2008 R2 SP1. I could not figure out how to resolve this issue, and not to pat myself on the back, I usually and eventually resolve something or get really close, but I was no where near close on this one, other than knowing it was an IIS issue. I eventually called Microsoft Support to assist in this scenario, instead of wasting any more of my time or the customer’s valuable productivity on the issue. That said, this will be the first time in two years that I’ve needed to contact Microsoft Support.

During the course of the support call, we discussed various ways to redirect the Default Site access by simply typing in, mail.domain.com, and have it redirect to https://mail.domain.com/owa, thus making it easier for users to remember the short URL instead of having to remember the whole URL.

I was originally following Brian Desmond’s blog on how to configure the redirect, and it works great. I’ve used it for a half dozen customers without incident for the past two years. But after I saw this method, I was astonished at the ease of configuration, and it does not affect any subfolders.

The idea behind it is configuring the IIS 7 and 7.5 HTTP Redirect feature on the actual iisstart.htm file, and not for the actual Default Website. If you set it for the website, you must uncheck it for each and every sub web folder which is a pain in the butt to go through each one, and you may make a mistake that can render Exchange useless. Support call anyone? Smile

This requires the IIS HTTP Redirect feature installed under Web Role Services

If you don’t already have it installed, you will need to install the HTTP Redirect feature under the IIS Web Server Role Services. If you don’t have it installed, it’s a quick installation that does not require a restart.

Steps to install the HTTP Redirect Feature:

Open Server Manager, and then expand Roles.
Right-click Web Server (IIS), and then choose “Add Role Services.”
Under Web Server section, scroll down to find and click to select the “HTTP Redirect” check box.
Click Next to complete the installation.
Click Close when done.

Steps to configure OWA Redirect in Exchange 2010 and 2013:

Click on the Default Website

Right Click Default Website
Choose “Switch to Content View“
For the full image, click here

In the middle pane, you will now see a list of all the sub webs. You will also notice the iisstart.htm file.

Right-click the iisstart.htm file

Choose “Switch to Features View“
For the full image, click here

In the left pane, you will now see “iisstart.htm” in the navigation tree

Click on iisstart.htm in the left navigation tree
For the full image, click here
In the middle pane, either (either one gets you to the same place)

Right-click HTTP Redirect, choose Open Feature

Double-Click on HTTP Redirect

Check the box that states, “Redirect requests to this destination“

Type in OWA URL, such as https://mail.domain.com/owa

Click Apply
For full image, click here

Open a command window, or if you already have a PowerShell window open, that will work, too.

Type in IISRESET
Hit <enter>
You’re done!

It’s that easy. And it will not affect any of the Exchange’s necessary subfolders, or any other part of IIS.

Easy, wasn’t it?

Exchange 2003 & 2007 OWA Redirect

Navigate to c:\inetpub\webroot
Right click anywhere in the middle pane
Choose New -> Text Document

Notepad will open
Type in (you only need this one line):

<% response.redirect(“https://mail.domain.com/owa”)%>

Then save the file

Click Save As
Type in “default.asp”
And yes, you MUST use the quotes so the system will not append “.txt” on the end of it and rendering it useless.

Click Save

Open IIS Management Console

If this is Exchange 2000 or 2003 on Windows 2000/2003, IIS6:

Navigate to the Default Website
Right click, properties
Under Default Document, make sure default.asp is at the top of the list. If it’s not, use the arrows to move it to the top.

Click Ok

Open the Command prompt

Type in IISRESET, then hit <enter>

If this is Exchange 2007 on Windows 2008, IIS7:

Navigate to Default Website
In the middle pane, Double-click on Default Document
Make sure default.asp is at the top of the list
Open the Command prompt

Type in IISRESET, then hit <enter>

References:

If you want to use Brian Desmond’s which works perfectly, too, and I’ve been using it for over two years without a hitch, here it is:

Redirecting OWA URLs in Exchange 2010, by Brian Desmond
http://briandesmond.com/blog/redirecting-owa-urls-in-exchange-2010/

Microsoft’s KB on OWA Redirect:

How to redirect requests from HTTP to HTTPS or to the OWA virtual directory in IIS 7
Applies to Microsoft Internet Information Services 7.0
http://support.microsoft.com/kb/975341

Simplify the Outlook Web App URL
Applies to: Exchange Server 2010 SP3, Exchange Server 2010 SP2
http://technet.microsoft.com/en-us/library/aa998359(v=exchg.141).aspx

How to redirect an HTTP connection to HTTPS for Outlook Web Access clients and how to redirect the Default Web Site to point to the Exchange virtual directory
Applies to Exchange 5.5, Exchange 2000, Exchange 2003 (Just thought to throw this in here for anyone still on the legacy Exchange versions)
http://support.microsoft.com/kb/839357

Comments, corrections, concerns, and suggestions are all welcomed!

Ace

AD & Dynamic DNS Updates Registration Rules of engagement

Posted on March 12, 2013 by Ace Fekay

Keep in mind, for the most part it automatically works “out of the box” without much administrative overhead.

Original Compilation: 11/19/2012

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Summary

The machine’s DNS entries in the NIC, must be ONLY configured to use the internal DNS servers that host the zone. No others.
a. DHCP Option 006 MUST only be the internal DNS server(s) you want to use, otherwise if using an ISP’s DNS or your router, expect undesired results.
The Primary DNS Suffix on the machine MUST match the zone name in DNS.
a. For joined machines, this is default.
b. For non-joined machines, it must be manually configured or scripted.
If using DHCP Option 015 (Connection Specific Suffix), it must match the zone name and have “Use This Connection’s DNS Suffix in DNS Registration” along with “Register This Connection’s Addresses in DNS” checked in the NIC’s IPv4, Advanced, DNS tab.
The Zone must be configured to allow updates.
For AD Integrated Zones and Secure Only Updates:
   a. If the machine’s network card DNS address entries have been statically configured:
      – They must only point to the internal DNS servers that host the AD zone or to servers that have a reference to the zone (such as stubs, secondary zones, conditional forwarders, or forwarders)
      – It must be joined to the domain in order to authenticate using Kerberos to update.
   b. If statically configured and not joined to the domain, the client can’t update its record if the zone is set to Secure Only.
   c. For non-joined domain DHCP clients, you can configure DHCP to update in lieu of the client updating into a Secure Only zone.
For any non-Windows statically configured machine, it must support the DNS Dynamic Updates feature and the zone configured to allow Secure and Unsecure updates.
If the DNS server is multihomed and not configured properly to work with multihoming, it may cause problems with Dynamic Updates.
If the zone is single label name, such as ‘domain’ instead of the proper minimal format of ‘domain.com,’ ‘domain.net,’ etc., it will NOT update.
The client will “look” for the SOA of the zone when it attempts registration. If the SOA is not available or resolvable, it won’t register. Keep in mind with AD integrated zones the SOA rotates among the DCs because of the multimaster feature. This is default and expected behavior, but if there are any DCs that have any problems, and the client resolved the SOA to that DC, it may not accept the update.
The zone in DNS must NOT be a single lable name, such as “DOMAIN” instead of the required minimum of two hierarchal levels such as domain.com, domain.local, domain.me, domain.you, etc. Single label name zones are problematic, do not conform to the DNS RFC, and causes excessive internet traffic to the Root Servers when DNS tries to resolve a single label name query, such as querying for computername.domain – in such a query, the domain name is actually treated as a TLD. ISC has made a note of the excessive traffic generated by Microsoft DNS servers configured with a single label name in 2004 with Microsoft, which in turn disabled the ability for Microsoft DNS in Windows 2000 SP4 and newer to resolve single label names without a registry band aid. More info on this:

Active Directory DNS Domain Name Single Label Names – Problematic
Published by Ace Fekay, MCT, MVP DS on Nov 12, 2009 at 6:25 PM 641 0
http://msmvps.com/blogs/acefekay/archive/2009/11/12/active-directory-dns-domain-name-single-label-names.aspx

For Windows 2008 and all newer operating systems, IPv6 must not be disabled. If disabled, it will cause other problems:
The Cable Guy – Support for IPv6 in Windows Server 2008 R2 and Windows 7, by Joseph Davies, Microsoft, Inc.
Quoted by Joseph Davies, MSFT:
“IPv6 is a mandatory part of the Windows operating system and it is enabled and included in standard Windows service and application testing during the operating system development process. Because Windows was designed specifically with IPv6 present, Microsoft does not perform any testing to determine the effects of disabling IPv6. If IPv6 is disabled on Windows Vista, Windows Server 2008, or later versions, some components will not function. “Moreover, applications that you might not think are using IPv6—such as Remote Assistance, HomeGroup, DirectAccess, and Windows Mail—could be.”
http://technet.microsoft.com/en-us/magazine/2009.07.cableguy.aspx

Arguments against disabling IPv6
Demoire, [MSFT], 24 Nov 2010 12:37 AM
http://blogs.technet.com/b/netro/archive/2010/11/24/arguments-against-disabling-ipv6.aspx
IPv6 for Microsoft Windows: Frequently Asked Questions
(Basically Microsoft is saying in this KB article to not disable IPv6)
http://technet.microsoft.com/en-us/network/cc987595.aspx

Full explanation:

Active Directory’s DNS Domain Name is NOT a single label name (“DOMAIN” vs. the minimal requirement of “domain.com.” “domain.local,” etc).
The Primary DNS Suffix MUST matches the zone name that is allowing updates. Otherwise the client doesn’t know what zone name to register in. You can also have a different Connection Specific Suffix in addition to the Primary DNS Suffix to register into that zone as well.
AD/DNS zone MUST be configured to allow dynamic updates, whether Secure or Secure and Non-Secure. For client machines, if a client is not joined to the domain, and the zone is set to Secure, it will not register either.
You must ONLY use the DNS servers that host a copy of the AD zone name or have a reference to get to them.

Do not use your ISP’s, an external DNS address, your router as a DNS address
Do not use any DNS that does not have a copy of the AD zone.
Internet resolution for your machines will be accomplished by the Root servers (Root Hints), however it’s recommended to configure a forwarder for efficient Internet resolution.

The domain controller is multihomed (which means it has more than one unteamed, active NIC, more than one IP address, and/or RRAS is installed on the DC).

The DNS addresses configured in the client’s IP properties must ONLY reference the DNS server(s) hosting the AD zone you want to update in.

This means that you must NOT use an external DNS in any machine’s IP property in an AD environment.
You can’t mix internal and external DNS server. This is because of the way the DNS Client side resolver service works. Even if you mix up internal DNS and ISP’s DNS addresses, the resolver algorithm may still pick the incorrect DNS to query. Based on how the algorithm works, it will ask the first one first. If it doesn’t get a response, it removes the first one from the eligible resolvers list and goes to the next in the list. It will not go back to the first one unless you restart the machine, restart the DNS Client service, or set a registry entry to cut the query TTL to 0. The rule is to ONLY use your internal DNS server(s) and configure a forwarder to your ISP’s DNS for efficient Internet resolution.
There is a registry entry to cut the query to 0 TTL (normally this is not necessary, but I’m posting it as a reference).

The DNS Client service does not revert to using the first server …The Windows 2000 Domain Name System (DNS) Client service (Dnscache) follows a certain algorithm when it decides the order in which to use the DNS servers …
http://support.microsoft.com/kb/286834

The DNS Client Service Does Not Revert to Using the First Server in the List in Windows XP (applies to all Operating Systems, too)
http://support.microsoft.com/kb/320760

For more info, please read the following on the client side resolver service:
DNS, WINS NetBIOS & the Client Side Resolver, Browser Service, Disabling NetBIOS, Direct Hosted SMB (DirectSMB), If One DC is Down Does a Client logon to Another DC, and DNS Forwarders Algorithm if you have multiple forwarders.
http://msmvps.com/blogs/acefekay/archive/2009/11/29/dns-wins-netbios-amp-the-client-side-resolver-browser-service-disabling-netbios-direct-hosted-smb-directsmb-if-one-dc-is-down-does-a-client-logon-to-another-dc-and-dns-forwarders-algorithm.aspx

For DHCP clients, DHCP Option 006 for the clients are set to the same DNS server.

If using DHCP, DHCP server must only be referencing the same exact DNS
server(s) in it’s own IP properties in order for it to ‘force’ (if you set
that setting) registration into DNS. Otherwise, how would it know which DNS
to send the DNS registration request data to?

If the AD DNS Domain name is a single label name, such as “EXAMPLE”, and not the proper format of “example.com” and/or any child of that format, such as “child1.example.com”, then we have a real big problem. DNS will not allow registration into a single label domain name.
This is for two reasons:

It’s not the proper hierarchal format. DNS is
hierarchal, but a single label name has no hierarchy.
It’s just a single name
Registration attempts causes major Internet queries
           to the Root servers. Why? Because it thinks the
           single label name, such as “EXAMPLE”, is a TLD
          (Top Level Domain), such as “com”, “net”, etc. It
          will now try to find what Root name server out there
          handles that TLD. In the end it comes back to itself
         and then attempts to register. Unfortunately it doe NOT
         ask itself first for the mere reason it thinks it’s a TLD.
Quoted from Alan Woods, Microsoft, 2004:
“Due to this excessive Root query traffic, which ISC found from a study that discovered Microsoft DNS servers are causing excessive traffic because of single label names, Microsoft, being an internet friendly neighbor and wanting to stop this problem for their neighbors, stopped the ability to register into DNS with Windows 2000 SP4, XP SP1, (especially XP,which cause lookup problems too), and Windows 2003. After all, DNS is hierarchal, so therefore why even allow single label DNS domain names?”
The above also *especially* applies to Windows Vista, Windows 7, &, 2008, 2008 R2, Windows 2012, and newer.

‘Register this connection’s address” on the client is not enabled under the NIC’s IP properties, DNS tab.

Maybe there’s a GPO set to force Secure updates and the machine isn’t a joined member of the domain.

With Windows 2000, 2003 and XP, the “DHCP client” Service is not running. In Windows 2008, Windows Vista and all newer operating systems, it’s now the DNS Client Service.

This is a requirement for DNS registration and DNS resolution even if the client is not actually using DHCP.
Dynamic DNS Updates Do Not Work if the DHCP Client Service Stops (2000/2003/XP only)
http://support.microsoft.com/?id=264539

You can also configure DHCP to force register clients for you, as well as keep the DNS zone clean of old or duplicate entries. The following has more information on how to do that:

DHCP, Dynamic DNS Updates, Scavenging, static entries & timestamps, and the DnsProxyUpdate Group (How to remove and prevent future duplicate DNS host records)
Published by acefekay on Aug 20, 2009 at 10:36 AM 3758 2
http://msmvps.com/blogs/acefekay/archive/2009/08/20/dhcp-dynamic-dns-updates-scavenging-static-entries-amp-timestamps-and-the-dnsproxyupdate-group.aspx

What will stop AD SRV registration:

Any DNS server referenced in TCP/IP properties that does not host the AD zone name, or does not have a reference to the internal AD zones name.

External DNS servers do not host or have a reference, therefore must NOT be used.
AD Domain machines must never be pointed at an external (ISP) DNS server or even use an ISP DNS server as an “Alternate DNS server” because they do not host the internal AD zone, or have a reference to it.

Only use internal DNS servers when part of an Active Directory domain. Active Directory’s Reliance on DNS, and why you should never use an ISP’s DNS address or your router as a DNS address, or any other DNS server that does not host the AD zone name
http://msmvps.com/blogs/acefekay/archive/2009/08/17/ad-and-its-reliance-on-dns.aspx

Are any services disabled such as the DHCP Client service or the DNS Client Service? They are required services, whether the machine is static or DHCP.

No DNS registration functions if DHCP Client Service Is Not Running (2000/2003/XP only)
http://support.microsoft.com/?id=268674
Dynamic DNS Updates Do Not Work if the DHCP Client Service Stops (2000/2003/XP only)
http://support.microsoft.com/?id=264539
For all Windows 2008, Windows Vista and all newer operating systems, it’s the DNS Client Service.

The AD/DNS zone not configured to allow dynamic updates.

Make sure ‘Register this connection’s address” in DNS is enabled under TCP/IP properties.

Missing or incorrect “Primary DNS suffix” or “Connection-specific DNS suffix” of the domain to which the machine belongs.

I one of these are incorrect, the client side service cannot find the correct zone to register into. If missing or incorrect, it is called a Disjointed Domain Namespace.

Is the firewall service enabled? (disable it).

Were the default C: drive permissions altered and was a hotfix installed a recently?

“Systems that have changed the default Access Control List permissions on the %windir%\registration directory may experience various problems after you install the Microsoft Security Bulletin MS05-051 for COM+ and MS DTC”
http://support.microsoft.com/kb/909444
For more info about this issue, see:
http://blogs.technet.com/steriley/archive/2005/11/08/414002.aspx

If the zone is set to Secure Updates Only, the computer may not have authenticated to the domain (which can be due to DNS misconfiguration or DNS server problem), which of course causes more problems than just DNS registration.

Is the File and Print services enabled?

It must be enabled.

Microsoft Client Services enabled?

If not, it must be enabled.

Is DNS service listening on the private LAN interface?

Check under the Interfaces tab under DNS server properties in the DNS console.

More than one NIC on a client?

The wrong one may be registering.

Updates allowed on the zone?

This is an obvious one.

Primary DNS suffix matches the zone name in DNS and the AD domain name?

If not, then it won’t register into the zone.

Was Zone Alarm ever installed on these machines?

If so, ZA leaves SYS files and other remnants that continue to block traffic.

Any Event log errors?

Was a Registry entry configured to stop registration?

246804 – How to Enable-Disable Windows 2000 Dynamic DNS Registrations (per NIC too):
http://support.microsoft.com/?id=246804

Spyware or something else such as DotNetDns installed on it?

Download the free tool at www.malwarebytes.com and run a malware scan.
Download the free Malicious Software Scanner from Microsoft and run a scan
Download TrendMicro HouseCall free scan tool and run it.

Single Label Domain Name?

Active Directory DNS Domain Name Single Label Names – Problematic – And this applies to any DNS zone name, not just AD.
Published by Ace Fekay, MCT, MVP DS on Nov 12, 2009 at 6:25 PM 641 0
http://msmvps.com/blogs/acefekay/archive/2009/11/12/active-directory-dns-domain-name-single-label-names.aspx

Netlogon and DFS services must be started.

Malware or virus altering network services preventing it from registering.

Some sort of firewall in place, whether the Windows firewall disabling File and Print Services, or a 3rd party firewall, which many AV programs now have built in and must be adjusted to allow this sort of traffic and exclude the NTDS and SYSVOL folders.
If Windows Firewall, run the following to see what settings are enabled:
netsh firewall show config

Is IPv6 disabled? That will stop registration.

Enable it.

Do any duplicate AD integrated zones exist in the AD database?

This will cause major problems. Any duplicates found must be deleted. The cause must also be determined to eliminate it from occurring again.
Using ADSI Edit to Resolve Conflicting or Duplicate AD Integrated DNS zones
Published by acefekay on Sep 2, 2009 at 2:34 PM 7748 2
http://msmvps.com/blogs/acefekay/archive/2009/09/02/using-adsi-edit-to-resolve-conflicting-or-duplicate-ad-integrated-dns-zones.aspx

Were imaged machines Sysprepped?

If not, duplicate SIDs will cause machines to fail authentication to register into the zone.

Suggestions, Comments, Corrections are welcomed.

Ace Fekay, MCT, MVP Directory Services

Troubleshooting the Browser Service

Posted on March 2, 2013 by Ace Fekay

By Ace Fekay, , MCT, MVP, MCSE 2012/Cloud, MCITP EA, MCTS Windows 2008/R2, Exchange 2007 & 2010, Exchange 2010 Enterprise Administrator, MCSE 2003/2000, MCSA Messaging 2003
Microsoft Certified Trainer
Microsoft MVP: Directory Services
Active Directory, Exchange and Windows Infrastructure Engineer
www.delcocomputerconsulting.com

Preamble:

Keep in mind, each subnet has it’s own master browser, and if you are using WINS, the master browser works together with the WINS service to enumerate an infrastructure wide browse list.

If not using WINS, it uses broadcasts, however, you’ll only see what’s on your own subnet, because NetBIOS broadcasts are more than likely blocked by routers, which is default, and many routers don’t allow NetBIOS broadcast across subnets to be enabled.

And if you are in a multi-subnetted environment, and you want full browsing capabilities, to get around routers blocking NetBIOS broadcasts, it’s suggested to use WINS.

And the default WINS settings out-of-the-box, work fine, as long as you set up DHCP WINS options correctly. There is no need to adjust WINS’ registry parameters, otherwise you’ll find yourself trying to change registry entries on multiple servers and mis-keying something. Here’s more info on configuring WINS:

WINS – What Is It, How To Install It, WINS Replication Partner Design Guidelines, How to Configure DHCP Scopes For WINS Client Distribution, and more:
http://msmvps.com/blogs/acefekay/archive/2010/10/27/wins-what-is-it-how-to-install-it-and-how-to-configure-dhcp-scopes-for-wins-client-distribution.aspx

Preferably install at least one server OS on each subnet:

If there is a server OS, and it’s not multihomed, especially if a DC on the subnet and it’s not multihomed (multihoming a DC is a really bad idea), then it should win, unless there’s a problem with the machine itself, such as some sort of security setting in your antivirus blocking traffic, or firewall blocking traffic on it.

If you find workstations are becoming masters, that means there are no server operating systems on those subnets, in such cases, the workstation will win Master Browser election.

And I realize in many large infrastructures, it would be nearly impossible to put a server operating system on each subnet. However, as long as there is a desktop using the latest client operating system that is always up and running 24/7, that will do the trick.

If a newer client OS were to be introduced, then it would start a master browser election, and win the election (OS version and server role is a factor in the election process). And any machine that someone clicks on Network Neighborhood or clicks a Browse button somewhere, would invoke an election, but if a desktop is running on the subnet 24/7, it will win the election, since it’s already up and running.

If you don’t want any other client machine to win the election and were to opt for only that one machine, you can set a registry entry using a GPO to disable participating in the browse list for all the machines in the subnet other than the client machine you chose to keep up and running 24/7:

Set the client machine of your choosing to:
Emulator MaintainServerList=Yes, IsDomainMaster=True

All other clients on the subnet, set it to:
MaintainServerList=Auto,IsDomainMaster=False

I’m not saying this is a perfect solution, but it’s something to consider. Otherwise, if no specific machine is up and running 24/7 on any given subnet, the browse list will be rebuilt each time everyone shuts down, then brings their machines up in the morning, and the cycle starts from scratch to rebuild the list of machines on that subnet.

Third Party Devices Participating in the Browser Service

I would like to point out that if you have any 3rd party devices, such as a Seagate BlackArmor NAS, it will jump in on the election process and may win, which in case will snafu your browse list. I had one of those devices at a customer site last year causing numerous problems with the browse list, which in turned snowballed to cause problems with Symantec BackupExec, and other services that rely on browsing.

After some troubleshooting, I found that the BlackArmor NAS was consistently winning the election causing the problems. I couldn’t find anything specific on how to disable browser service participation on the device. It has the latest firmware. I contacted Seagate, and they said they couldn’t help me to disable the device’s ability to participate in the Browser Service.

I finally moved it on to its own VLAN so it can be king of itself on that subnet, so to speak. I gave it it’s own island. Smile

Browse List Propagation:

We have to keep in mind with troubleshooting the browser service, there is a time period you have to wait for the list to fully enumerate and become available on the master. A good example is when a server is shut off on a segment, and the workstations kick in, or the server is rebooted, wins the election, and begins a new cycle to enumerate the browse list from WINS and/or broadcasts. This can take a minimal of 12 minutes, upwards to the 48-minute full propagation cycle in a multiple-segment domain environment.

When to Troubleshoot

Below are the generic troubleshooting steps I used to troubleshoot the browser service that helped me find out the BlackArmor device was the culprit.

If you are seeing problems with the browser service, such as computers disappearing from the browse list, whether the cause is a third party device, Unix/Linux machine running Samba, or simply based on the infrastructure’s design, it might be a good idea to start troubleshooting to find the culprit.

Prepare to Troubleshoot:

Make sure the Computer Browser service is Started. Make sure NetBIOS is enabled on al machines.
On Windows 2003 and 2000, install the Support Tools (from the Windows CDROM) in order to have the “browstat” utility available.
With Windows 2008 and newer, the utility is already installed as part of the operating system files.
If there are any antivirus software, third party firewalls, or firewall rules between locations blocking WINS traffic (TCP 42), it could block browser traffic, too. This of course, assumes the Computer browser service is running.

Firewall blocks – Test it with PortQry

You can use the Portqry.exe utility to test if the Browser, SMB, WINS and the ephemeral (service response) ports are permitted.

Browser: UDP 137/138, TCP 139
SMB: TCP 445
WINS: TCP 42
Ephemeral (Service Response Ports): Varies depending on OS:
- Windows 2000/2003/XP: TCP/UDP 1024-5000
- Windows 2008/Vista and newer: TCP/UDP 49152-65535

Description of the Portqry.exe command-line utility
http://support.microsoft.com/kb/310099

Active Directory Firewall Ports – Let’s Try To Make This Simple
http://msmvps.com/blogs/acefekay/archive/2011/11/01/active-directory-firewall-ports-let-s-try-to-make-this-simple.aspx

Multihomed DCs:

And if you have any multihomed DCs, among numerous other problems, that is a major cause of browser problems. Multhoming DCs is not recommended for multiple reasons, including a “Multihomed Browser” scenario. I suggest to disable one of the interfaces.

More info regarding multihoming DCs and why not to do it:

Multihomed DCs (with more than one unteamed NIC or multiple IPs) with DNS, RRAS, iSCSI, and/or PPPoE adapters – A multihomed DC is not a recommended configuration, however there are ways to configure such a DC to work properly.
http://msmvps.com/blogs/acefekay/archive/2009/08/17/multihomed-dcs-with-dns-rras-and-or-pppoe-adapters.aspx

Troubleshooting Steps:

Run a browstat status to see who the browse master is for the segment. If it’s not the PDC Emulator, and some other device won the election, that can cause a problem.

To check current status of the browse service on the domain, run:
browstat status

You should get a response similar to:
Browsing is active on domain.
Master browser name is: <serverName>

Note, the machine that is the current master browser will either be, depending if the machine type exists on the segment: the PDC Emulator, a replica DC on the segment, a member server, joined workstation, or workgroup member, Unix or Linux with SAMBA, etc.

If you find a device is winning the election, then we need to disable that ability in the device. If there are no features for that, contact their support department, or put the device behind it’s own subnet or VLAN to prevent it from winning the election on the production network.

To find the current browse master on a segment, you’ll have to find the TransportID:
First run:

browstat getmaster \device\netbt_el59x1 <domainname>

It will error out because the “netbt_el59x1″ probably doesn’t exist, and will respond with the transports currently bound to the browser. Copy and paste the transport that does show up into your next command:

browstat getmaster \Device\NetBT_Tcpip_{C2055954-4F86-446F-ACBA-E00BE731C3FB} <domainname>

Force an election by running:
browstat elect \device\netbt_ieepro1 <domainname>

Then check the event logs to see which machine won the election. If it’s a device, such as I’ve found that Linux/Unix with SAMBA, or devices such as a Seagate NAS, may win the election and cause browsing havoc within an environment and get that familiar, but unwanting “Access Denied” when trying to browse.

Reference:

Troubleshooting the Microsoft Browser Services:
http://support.microsoft.com/kb/188305

Comments, corrections and suggestions are welcomed.

Ace Fekay

So you want to change your IP range?

Posted on March 2, 2013 by Ace Fekay

So you are looking at a major IP migration from a public range to a private range and not simply extending the current scopes, or you simply want to change the current IP range.

One good reason to change the internal IP range, is the current range matches many of the retail box store router default IP subnets, such as from Linksys, Netgear, etc. The identical subnets cause issues when users at home are using VPN to the company network. If the subnets are identical, routing won’t work, therefore they are never able to connect or access internal company resources.

Depending on the size of the infrastructure, changing the IP range can either be easy, or pretty involved and will have a major undertaking on your hands. Let’s see…

First come up with an IP Range

Come up with a plan that includes an IP range for all servers and static set hosts, as well as an IP range for each floor, building, etc., depending on the scope of this project, and the subnets currently in place.

You could use the same subnet for the whole building, which makes it easier to deal with, but not necessarily as efficient with network traffic, and especially if the number of hosts is so large (into the thousands), it becomes a rather large subnet broadcast domain. Also with one big subnets, you are reducing the ability to create efficient AD Sites appropriately.

For example, if one were to choose one subnet for a large building with 3000 users, you could use one subnet, such as 10.10.0.0/16, which will give you 65,000 IPs:

If you want to keep with the separate subnets for each floor, which is ideal, of course considering if you have layer 3 VLAN capable switches, that may be your better bet. Some may think it complicates matters with DHCP and routing, but looking at the network efficiency, I think it’s a better bet.

For example, if you have multiple subnets or buildings with less than 4000 total hosts (servers, users, printers, etc.), a good example is the following breakdown, which will give you 4096 hosts for each subnet (and this is just an example – your mileage may vary):

10.10.0.0/20 (10.10.0.0 – 10.10.15.255)
10.10.16.0/20 (10.10.16.0 – 10.10.31.255)
10.10.32.0/20 (10.10.32.0 – 10.10.47.255)
10.10.48.0/20 (10.10.48.0 – 10.10.63.255)
etc

Procedure (steps are not in stone)

Inventory all applications that have been configured with hardcoded IP addresses in their configuration, then change the IPs to the new IPs.
Ask users to shutdown all workstations.
Change the DC/DNS server’s’ IP addresses.
1. In NIC properties, change it to the new IP address.
2. In NIC properties, change the DNS IP addresses to the new IP.
3. Re-register the DCs in DNS so it re-creates new records.
  1. ipconfig /all
  2. restart netlogon service
4. Reference: Change the static IP address of a domain controller
  http://technet.microsoft.com/en-us/library/cc758579(WS.10).aspx
Check DNS:
1. Server properties, Nameservers tab, insure the new IPs are listed.
2. Remove the old ones and re-enter if needed.
3. Check DNS zones – Make sure all old IP references are manually removed if the registration process above does not overwrite the old ones, which it should.
4. Check the GC records (located in gc. _msdcs.domain.local).
5. Check the LdapIpAddress records – the “same as parent” A records that each DC registers.
Create a new reverse zone for the planned IP subnets. Make sure updates are allowed.
1. Delete the old reverse zone.
2. In lieu of deleting and recreating the reverse zones, if you’re energetic:
  1. Change the AD integrated reverse zone to a Primary Standard zone (this takes it out of AD and puts it into a text file in system32\dns.
  2. Open the system32\dns\zoneName.dns file, and change all the IPs in the zone file, save it, reload the zone. You should see all the new IPs
  3. Then change it back to AD integrated again.
Change the DHCP Server’s scope.
1. You will need to delete and re-create the scope from scratch.
2. If you have Scope Options recreate the Scope Options.
3. If you have Server Options, simply change the IP addresses they point to.
  1. If using WINS, change DHCP Option 044 to the new IP address of the WINS server.
  2. Option 003 is the router
  3. Option 006 is for DNS addresses
If using Windows RRAS for VPN, and you are using a static IP pool, change the pool to a range in the new IP range.
1. If using any other VPN solution, likewise.
2. If using a Relay Agent or IP Helper, change the IP it’s pointing to.
If using RRAS for NAT, change the configuration to the new internal interface’s IP.
Change all of your other servers’ IPs.
1. Run ipconfig /registerdns
Change any static hosts, including printer cards, and other IP static entries.
1. Restart the printers to take effect.
With Windows machines, start them up.
1. If they haven’t been shut down, then run ipconfig /registerdns on each.
Make sure the above works, AD is functional, the DCs and servers can get to the printers, etc.
You can run tests such as for Windows 2000 – 2008 R2, dcdiag /v /fix, and if Windows 2003 and older, run netdiag /v /fix.
Check Event logs for any errors.
Change the internal IP of the router.
Recreate port-mappings (port translations) on the firewall, if required.

Do Multiple Internal Subnets exist?

If using multiple internal subnets that you are currently connected to, change the static route entries on the edge firewall/router to insure communications work to the other subnets. The same on their end.
Once again, check event logs for any errors.
Test internet connectivity from your DCs and servers.
DHCP – Take note of exclusions, reservations, SuperScopes, etc. Delete all scopes.
Create a new big scope, or multiples if you had separate scopes, Superscopes, etc.
Test DHCP by firing up a couple of workstations, logons, internet connectivity, printers, resource access, etc.
Once again, check event logs for any errors.

I’m sure I may have missed a few steps and only briefed over others, but it should give you a good start and a guideline, because every infrastructure is different and unique.

Comments, corrections and suggestions are welcomed.

Why do we ask for an ipconfig /all, when we try to help diagnose AD issues?

Posted on March 2, 2013 by Ace Fekay

Ace Fekay, MCT, MVP, MCSE 2012/Cloud, MCITP EA, MCTS Windows 2008/R2, Exchange 2007 & 2010, Exchange 2010 Enterprise Administrator, MCSE 2003/2000, MCSA Messaging 2003
Microsoft Certified Trainer
Microsoft MVP: Directory Services
Active Directory, Exchange and Windows Infrastructure Engineer
www.delcocomputerconsulting.com

Ace here again. Yea, I had to post a blog about this because many people ask, why do you want that? Just for the IP address??

Nope. Not just for the IP.

Good question.

There is quite a bit of information that an ipconfig /all provides us configuration data as a precursor for a diagnosis. Sometimes the ipconfig /all results will help us fix it, but not always.

Many admins are reluctant to provide this sort of information citing security reasons.

In some cases, I sympathize and agree, but in many cases, security really isn’t much of a concern, because for one, your internal IP range is a private range, and two, you can substitute your actual internal domain name with something more generic, such as substituting “microsoft.local” with “mydomain.local. You should also substitute your DC names using something generic, such as dc-01. dc-02, etc. But definitely keep track of the substituted DC names if we have additional questions regarding them.

Let’s take a look at each value in an ipconfig /all

Believe it or not, the results of an ipconfig /all has numerous information that helps us get an inside view of a DC’s basic network configuration, as well as basic service configuration.

Let’s break it down:

C:\>ipconfig /all

Windows IP Configuration

Host Name . . . . . . . . . . . . : company-dc-01

Name is under 15 characters – good for NetBIOS compatibility. Not a huge concern for many compani
Possibly indicates more than one DC based on the –01 portion of the name

Primary Dns Suffix . . . . . . . : company.com

The AD DNS Domain name is not a single label name.

In some cases, we’ll also ask for the name in ADUC. If the name in ADUC does no match this name, then it’s a Disjointed Namespace condition).

Node Type . . . . . . . . . . . . : Hybrid

If Hybrid is set, it tells me that WINS is in use.

Hybrid mode, specifically 0×8 (as you would set a WINS server Hybrid mode in DHCP Option 046), tells the client side resolver to use WINS first when attempting to resolve a single name query, and if it can’t resolve it, to then try a broadcast to resolve it. Of course, this is only after DNS resolution fails, since DNS is used first anyway, where the client side resolver will suffix the Search Suffix when attempting to resolve it as a DNS hostname query.

If the Node Type is set to “Unknown,” then no big deal. It just means that WINS is not being used, and the resolver service will use broadcast for a single name resolution.

IP Routing Enabled. . . . . . . . : No

Means RRAS is not installed
If set to Yes, it means RRAS is installed, and it will interfere with AD communications on this DC.

WINS Proxy Enabled. . . . . . . . : No

On a DC, “No” is what we want to see.
If set to Yes, then it means “Enable broadcast name resolution” is checked under General tab in RRAS properties.
- If this is set to Yes, and there is only one NIC. it could mean either:
- RRAS is installed only for VPN use
- RRAS was disabled, but the setting stuck
Either way, if it is set to Yes, it will cause problems with AD communications.

DNS Suffix Search List. . . . . . : company.com

This is what the client side resolver will use when attempting to resolve a single name query. For example, if I run nslookup against a single name such as computer1, the resolver will suffix company.com to it, resulting in a query of computer1.company.com.
If there are multiple domains in the forest, such as a parent and child domain, or multiple child domains, then each domain must be configured with a search suffix for all other domains in order to be able to resolve everything in the forest. This is also true for additional Trees in the forest.
The company.com in this example, was devolved from the Primary DNS Suffix.
- If the Primary DNS suffix has multiple levels, such as Chicago.ad.company.com, then the resolver will devolve it to show search suffixes of chicago.ad.company.com, ad.company.com, and company.com.
- However, if ad.company.com is the parent root domain, if using Windows 2008 or newer, it will only devolve to ad.company.com. Windows 2000 and 2003 devolved all levels, which led to some confusion.

Ethernet adapter Team 1:

Obviously this interface is a team.

Connection-specific DNS Suffix . :

If this is a DHCP client, and DHCP Option 015 is configured with a domain suffix, then it will populate this value. It’s used for a specific interface that gets this configuration, such as if it is a wireless, then that value will populate the wireless connection, but not the wired connection, and will be used as suffix for identification and DNS registration only for that interface, but it is not used as a search suffix.

Description . . . . . . . . . . . : BASP Virtual Adapter

This is the vendor brand name of the adapter

Physical Address. . . . . . . . . : 00-18-8B-47-F0-D1

This is the MAC address of this adapter or Team.

DHCP Enabled. . . . . . . . . . . : No

This means the NIC has a static configuration.

IP address, mask and subnet

   IP Address. . . . . . . . . . . . : 192.168.80.10
   Subnet Mask . . . . . . . . . . . : 255.255.255.0
   Default Gateway . . . . . . . . . : 192.168.80.1

In the above three values, we make sure the IP address and mask are on the same subnet as an ipconfig /all of another machine, if one was provided. You would be surprised how many times we’ve seen subnets mis-configured with an incorrect subnet mask.

DNS Servers . . . . . . . . . . . : 192.168.80.5
192.168.80.10

What we look for with DNS address, is only to specify the internal DNS servers hosting the AD zone. If an external DNS addresses are specified, or your router’s DNS address is specified (for example, 192.168.80.1), then you should expect to see numerous problems. This is because your machine is sending the external DNS servers or your router a query whenever it tries to login, authenticate, find domain resources, etc. The external DNS servers or your router, does not have an answer when queried for internal resources. It’s the same as me asking the first person I see walking by out front of my house, “Where’s that beer that was in my refrigerator last night?” Besides the person not having an answer, he’ll probably give me a funny or dirty look. Your DNS server and DC won’t give you a funny look, but you’ll probably get some sort of error and your machine will fail to find your AD domain.
The addresses you see listed in this example are showing that it is pointing to a partner DC as the first entry, and itself as the second entry.
- You may also find in some configuration the loopback as the second entry. This is ok, too. DCPROMO puts in the loopback. Matter of fact, if you were to run the AD BPA, one of the things it looks for is the loopback as the second entry. You can leave it there if you like, or you can change it to the IP of itself, but if you do, just ignore the BPA’s warnings, if you were to run it again.

Primary WINS Server . . . . . . . : 192.168.80.10

This tells me the server is running WINS. Why? Because it is pointing to itself, as it should be for a WINS server.
If a WINS server is pointing to any other WINS servers, it will cause numerous problems with WINS record ownership.

NetBIOS over Tcpip. . . . . . . . : Enabled

Of course this one is obvious. But here’s one for you. If you have NetBIOS disabled, but you are using WINS, what’s the point??

Do I need NetBIOS?

Posted on March 2, 2013 by Ace Fekay

By Ace Fekay, MCT, MVP, MCSE 2012/Cloud, MCITP EA, MCTS Windows 2008/R2, Exchange 2007 & 2010, Exchange 2010 Enterprise Administrator, MCSE 2003/2000, MCSA Messaging 2003
Microsoft Certified Trainer
Microsoft MVP: Directory Services
Active Directory, Exchange and Windows Infrastructure Engineer
www.delcocomputerconsulting.com

Do you need NetBIOS? That Depends …

Previous to Windows2000, Microsoft OS could only use SMB over a NetBIOS session. This means that all SMB traffic will start after NetBIOS session is established. It’s relies on TCP port 139. If we disabled the NetBIOS over TCP/IP, the SMB connectivity was interrupted.

With Windows 2000 and higher version, the OS support both NetBIOS sessions and Direct Hosting. That’s because Windows 2000 and newer will try to connect simultaneously over NetBIOS (port 139) and DirectSMB (port 445). If no response from the target on 445, it reverts back to 139. This offers legacy support for NetBIOS based apps. That is why if you disable NetBIOS on a server, it will still connect to other servers, but any NetBIOS based apps that require connectivity to that server will fail.

If you run a netstat -a, you can see port 445. It may even define it as Microsoft-DS, which means Microsoft DirectSMB. I know Vista doesn’t, but Windows 2003 will.

What’s TCP port 445 used for in Windows 2000/XP?
http://www.petri.co.il/what’s_port_445_in_w2k_xp_2003.htm

Quick Brief on NetBIOS and Those Noisy Broadcasts

Any machine that is NetBIOS capable (Windows, or Unix/Linux machines with SAMBA installed), will participate in a NetBIOS environment and with the browser service. Any NetBIOS capable machine will broadcast their NetBIOS computer name every 60 seconds, “Hey, my computer name is Computer1, and my IP address is <enterIP>, and I am offering the Workstation Service and Server Service on such and such workgroup and/or domain.”

WINS is a NetBIOS name to IP database. It’s a flat database with no hierarchal structure – simply one name to one IP. It’s similar to DNS, but DNS is hierarchal (child3.child2.child1.domain.com, etc.).

When you install WINS and configure all machines to use WINS, then the NetBIOS aware processes and functions will recognize there is a WINS server configured, and instead of broadcasting every 60 seconds, it simply registers its name and related services to the WINS database instead of repeatedly broadcasting, or simply put, it shuts up yelling out its name every 60 seconds.

Without WINS, it’s like a grade school cafeteria with all the background chatter, conversation, etc. With WINS, think of it as the kids in the cafeteria quietly enter their names, thoughts into a database and the other kids can read the database, so there is no more noise. Kind of like if every kid were to be yelling back and forth using Facebook using a table or smartphone in front of them, instead of peeping one word.

Therefore, WINS literally quiets the network. Period. But all machines must be configured with WINS to make this happen.

When a WINS enabled client needs to resolve a name, it really tries to resolve it first by DNS (hostname resolution process), and if only that doesn’t work, only then does it query WINS. If WINS isn’t configured, it would have used broadcast to find it, and if WINS doesn’t have the name entered in the database, it will use broadcast to find it.

The Computer Browser services enumerates and assembles the Browse List (the neighborhood) using Broadcasts. If WINS is configured, it will use the WINS database to assemble the browse list. This is why without WINS, the browse service can only assemble the local subnet, since NetBIOS does not travers across subnets. WINS provides multi-subnet support for NetBIOS resolution as well as enterprise-wide browse list so any machine anywhere in a network can browse to a machine anywhere else in a network, such as a machine in NY can browse to a machine in San Fran.

Joining a machine to the domain.

Yep, you need it to join a machine.

Windows 7 or Windows Server 2008 R2 domain join displays error “Changing the Primary Domain DNS name of this computer to “” failed….”
http://support.microsoft.com/kb/2018583

Network and Printer Browsing

The only complaints I’ve heard is losing network and printer browsing capabilities across subnets, since the browser service compiles the browse list from broadcasts, but broadcasts do not traverse routers to reduce excessive traffic across WAN links.However, I can’t substantiate the complaints, since all small to medium sized installations I’ve worked with kept NetBIOS enabled and used WINS.

Then again, you can use AD printer publishing for that feature and search AD for printers (when you share a printer, there’s a checkbox to publish it in AD).

WINS

Your best bet for smooth sailing with multi-subnet browsing and to support legacy apps is to use WINS.

Legacy Apps Require NetBIOS

So the biggest caveat is with legacy apps that rely on NetBIOS. For example, SEP and McAfee ePO uses the browser service, not DirectSMB, and they will fail with central control, updates, etc.

If you disable NetBIOS over TCP/IP, it causes functionality issues with ePO 4.x
https://kc.mcafee.com/corporate/index?page=content&id=KB76756&cat=CORP_EPOLICY_ORCHESTRATOR&actp=LIST

Environmental requirements for agent deployment from the ePO 4.x server
https://kc.mcafee.com/corporate/index?page=content&id=KB56386

Same with Backup Exec and backup agents. There are many other apps that require NetBIOS functionality.

What I can say is that some legacy applications and services still require WINS that AD DirectSMB doesn’t support, some of these apps include, but not limited to are:

Exchange 2003 with certain Outlook features
McAfee Enterprise ePolicy Orchestrator
Symantec Endpoint Protection
Symantec Backup Exec
Computer Associates AV
SQL
Mapped Drives
Printer sharing (not published in AD)
and many more….

Exchange 2000/2003 Need NetBIOS

Yea, I know this is the day and age of Windows 2012 and Exchange 2013, but believe it or not, there are still installations out there that are running legacy operating systems and Exchange, so I had to throw this in there.

Exchange 2000/2003require NetBIOS is Exchange 2003 for Outlook-Exchange Free/Busy communications.

WINS is still required with both Exchange 2000 and 2003
Aug 8, 2005 … See why Exchange needs WINS and how you can get a WINS server up and running and configure Exchange to use it. …
http://articles.techrepublic.com.com/5100-10878_11-5820760.html

WINS and Exchange 2003 Server Dependencies:
I had been laboring under the delusion that Windows and Exchange 2003 servers no longer need WINS, it seems that I was wrong. However, what I now believe …
http://www.computerperformance.co.uk/w2k3/services/WINS_exchange.htm

Exchange Server 2003 and Exchange 2000 Server require NetBIOS name …
You may have to use NetBIOS name resolution across different subnets for the … The following Exchange functionality still depends on WINS name resolution: …
http://support.microsoft.com/kb/837391

So you have to ask yourself, what else are you running?

Search Suffixes

Search Suffixes are used to facilitate single name resolution. As long as the search suffix is properly configured for your infrastructure, you should be ok.

Configuring DNS Search Suffixes
http://msmvps.com/blogs/acefekay/archive/2011/02/12/configuring-dns-search-suffixes.aspx

Suggestions, Corrections, & Comments are welcomed.

Ace Fekay

AD Site Design and Auto Site Link Bridging, or Bridge All Site Links (BASL)

Posted on February 24, 2013 by Ace Fekay

Preface

Ace here again with something I really would like to discuss, since this topic comes up from time to time.

To properly designed an AD multi-site infrastructure, there are a few things that need to be taken into account. I won’t bore you with all the background techno babble, rather I’m going to discuss a no-nonsense, get down to business on why you need to either keep Auto Site Link Bridging enabled, or why you need to disable it, both of which depends on your physical routed topology design.

AD Sites

First, a basic understanding of Active Directory Sites is important to understand before I go further.

Some of the biggest questions I hear about AD Sites are:

What are AD Sites?
What are AD Sites for?
Why can’t I create an AD Site without a domain controller in the Site?

These are all valid questions. A little research will usually result in an answer, but you may have to dig through piles of technical details to get to it. Let’s address each one:

What are AD Sites?

An AD Site defines a highly-connected, physical network locations in Active Directory. We define them by IP subnet or subnets. And yes, you can have multiple subnets that are highly-connected by routers within a location. In some cases, for example, if you have a very high-speed backbone, such as an OC-1 (51.84Mbps or higher), between locations, you can put all those subnets in one AD Site. However, in many cases, we probably don’t want to do that. Hang in there, I’ll be getting to that in a few minutes.

What are AD Sites for?

AD sites are basically used for two things:

To facilitate service localization. In simple English, this means to control logon and authentication traffic to DCs in a specific location, or Site. After all, we don’t want a client in NYC to pick a DC in Seattle, Japan, or somewhere else, to send its logon or authentication request (such as when accessing a folder), do we? Nope. The client side DC Locator process will find a DC in its own Site by using the client’s IP address.
To manage DC replication traffic. In simple English, this means to control DC replication traffic across WAN links between the bridgeheads (the DCs in a Site that communicate with DCs in other Sites). By default, replication between Sites are compressed down to 15% of total traffic. And with Sites, we can control frequency of replication, and when we’re allowing it to happen.’

Why can’t I create an AD Site without a DC in the Site?

Good question. If you look at what AD Sites are for, then it should be pretty obvious that you need a DC in it. After all, if there is no DC in it, and a client picks a Site based on its IP subnet, then looks for a DC, it won’t find any, will it? Nope, so it may wind up randomly picking a DC in another location, such as that DC in Seattle or Japan.

DC Locator Process

I don’t want to dwell on this, but I will briefly mention it because this is part of the reason why we want to create AD Sites anyway.

There is a process that a client uses to pick a DC. Here’s a quick view of how a client picks a DC. I should add a #9 to the list in a scenario when no DC exists in the Site, then it uses Automatic Site Coverage, and this ONLY if you created an IP Site link to another Site that you want the DCs to cover that site.

If you didn’t create an IP Site link for a Site that has no DCs, then it will pretty much become a random process, sort of, by using other factors, such as subnet netmask ordering and Round Robin. If you want to read up on this subject, here are two good Technet Forum discussions on it:

Briefly, here are the DC Locator process steps, and these steps were directly quoted from How Domain Controllers Are Located in Windows XP

Client does a DNS search for DC’s in _LDAP._TCP.dc._msdcs.domainname
DNS server returns list of DC’s.
Client sends an LDAP ping to a DC asking for the site it is in based on the clients IP address (IP address ONLY! The client’s subnet is NOT known to the DC).
DC returns…
1. The client’s site or the site that’s associated with the subnet that most matches the client’s IP (determined by comparing just the client’s IP to the subnet-to-site table Netlogon builds at startup).
2. The site that the current domain controller is in.
3. A flag (DSClosestFlag=0 or 1) that indicates if the current DC is in the site closest to the client.
The client decides whether to use the current DC or to look for a closer option.
1. Client uses the current DC if it’s in the client’s site or in the site closest to the client as indicated by DSClosestFlag reported by the DC.
2. If DSClosestFlag indicates the current DC is not the closest, the client does a site specific DNS query to: _LDAP._TCP.sitename._sites.domainname (_LDAP or whatever service you happen to be looking for) and uses a returned domain controller.

Brief overview:

For a full-sized image, click here.

Let me point out again, that if there are no DCs in a Site, then Automatic Site Coverage will take over.

To me, it’s a process to “find” a DC that will authenticate a user in a Site without a DC. However, my take on it is I would rather associate the location’s subnet to a current Site so as to not make the client go through this process. Besides, there may be scenarios that not having a DC in a Site can directly affect directory enabled applications and services such as DFS site referrals, SCCM or Exchange with it’s high dependency on GCs and DSAccess.

Here’s the process, directly quoted from the Technet article, “How DNS Support for Active Directory Works:”

Build a list of target sites — sites that have no domain controllers for this domain (the domain of the current domain controller).
Build a list of candidate sites — sites that have domain controllers for this domain.
For every target site, follow these steps:
1. Build a list of candidate sites of which this domain is a member. (If none, do nothing.)
2. Of these, build a list of sites that have the lowest site link cost to the target site. (If none, do nothing.)
3. If more than one, break ties (reduce this list to one candidate site) by choosing the site with the largest number of domain controllers.
4. If more than one, break ties by choosing the site that is first alphabetically.
5. Register target-site-specific SRV records for the domain controllers for this domain in the selected site.

If there are no DCs in a Site, you can use PowerShell to figure out which DC in which Site will be picked. If you like, you can further read up on the commands used to figure this out in Sean Ivey’s blog:

Sites Sites Everywhere…, By Sean Ivey, Microsoft DS PFE
http://blogs.technet.com/b/askds/archive/2011/04/29/sites-sites-everywhere.aspx

So wouldn’t you want your clients to pick a DC in its own Site?

Moving forward, do we really want a client to pick a DC in some other site or go through the Automatic Site Coverage process? Would you want that? I ‘m sure you already know the answer to that.

Therefore, if you have a location that have no DCs, then simply create an IP subnet object, and associate the subnet object to an existing AD Site that you want those users to use. In this case, you may base your own pick on a site linked by the fastest WAN link, or the only WAN link.

Auto Site Link Bridging

This now brings us to bridging, what it is, etc.

Within an AD Site, the KCC (Knowledge Consistency Checker) will automatically assume that all DCs can directly reach each other, and create Intrasite replication partnerships between the DCs in the Site. The one point that I want to be clear about that no matter how many DCs are in a Site, and there can be hundreds of DCs in a Site, the KCC will make sure that the partnerships created are done so that all DCs in a Site will have an updated replication set for any changes by any of the DCs in the site, within 15 minutes. If you add a new DC to the Site, the KCC jumps in and evaluates the new guy and adds it so it gets updated data from other DCs under 15 minutes. How does it do that? It follows a set algorithm, but that is beyond this discussion.

When there are multiple Sites, and more specifically three or more Sites, and keeping in mind that by default AD automatically assumes that all the Sites have direct physically connectivity and communications between each other. This means you can literally ping a DC from in any Site to any other Site.

Now the ISTG (Intersite Topology Generator) kicks in. The ISTG is a component of the KCC. It evaluates the overall topology, and builds connection objects between servers in each of the sites to enable Intersite replication— DC replication between sites.

Here’s a fully routed infrastructure, For the full-sized image, click here.

Sites cannot directly communicate with each other

However, if your physical network topology is designed where each site does not have direct communications with each other, and you leave all the default Auto Site Link Bridge settings as is, then lots of things will go wrong, such as replication problems, duplicate AD integrated zones, and more … keep reading. But I won’t address duplicate zones. You can click the link in the previous sentence for more on that.

Remember, by default, the KCC assumes all sites can directly communicate, therefore it will create partnerships between Bridgeheads in all sites. And any DC in a site can automatically become a bridgehead.

So if corporate headquarters is in NYC, and you have three remote locations, Miami, Chicago and Seattle, and direct communications does not exist, meaning that each remote location can only communicate with headquarters, and IP routing has not been configured between the remote locations, and the KCC creates a connection object (partnership) between a DC in Miami and a DC in Seattle, what will happen?

Since they can’t directly communicate, then replication fails. And if the Seattle partnership is the only connection object Miami may have, but Seattle happens to have one to NYC, and keeping in mind, replication is a PULL request, then Seattle will receive replication from NYC, but Miami can’t pull anything from Seattle, because there is no direct or indirect communications. So Miami winds up being in a secluded island.

In Miami’s DC’s view, it thinks no one wants to talk to it, so it will complain (you will see multiple event log errors) that others having replicated with it. And according to the DCs in the other sites, they will all think the same thing about Miami.

So who’s right? Of course, they all are. If the lack of replication goes beyond the AD Tombstone, then Miami would need to be demoted. Then again, you can’t even do that because it doesn’t have direct communications with its partner. Then if it does pick a DC in headquarters to demote, you will see an error stating that the headquarters DC already thinks the DC no longer exists. In the case of trying to demote it, or even forcedemoting it beyond the Tombstone, then your only option is to unplug it, run a metadata cleanup and re-promote it. But wait, then the same thing will occur if you don’t disable BASL.

So is it right that we do the same thing over and over and expect different results? Nope. Let’s configure AD to make sure it will not happen again, by disabling BASL.

Here’s a non-fully routed infrastructure. For the full-sized image, click here.

Disable BASL

Simply put, what we need to do is disable BASL (Bridge All Site Links) in a non-fully routed infrastructure to tell the KCC to only partner DCs across a specific site link.

Yes, that means you also have to create specific IP site links between headquarters in NYC to each site, as the image above shows.

And even if you have 20 sites all fully routed EXCEPT for one of them, then the same thing goes. You must disable it all because of that one site, otherwise the KCC will partner with a DC that it may not have direct communications with.

How to disable BASL. For the full-sized image, click here.

Summary

If you want to make sure your AD infrastructure is properly purring along and doing its job, then by all means let’s design it properly, make the necessary modifications, and other changes, to get it going in the right direction.

Oh, and you can’t forget to bone up on your DNS knowledge and how it supports AD. All Sites get registered in DNS by the netlogon service. Read more:

How DNS Support for Active Directory Works
http://technet.microsoft.com/en-us/library/cc759550(WS.10).aspx

And to understand the DNS SRV records registered by a DC’s Netlogon service, read Sean Dubey’s blog, with DNS SRV records examples, once again, I refer you to Sean Ivey’s blog:

Sites Sites Everywhere…, By Sean Ivey, Microsoft DS PFE
http://blogs.technet.com/b/askds/archive/2011/04/29/sites-sites-everywhere.aspx

References

Designing the Site Topology
http://technet.microsoft.com/en-us/library/cc787284(WS.10).aspx

Detailed branch office deployment guide (downloadable doc)
http://www.microsoft.com/downloads/details.aspx?FamilyId=9353A4F6-A8A8-40BB-9FA7-3A95C9540112&displaylang=en

Best Practice Active Directory Design for Managing Windows Networks
http://technet.microsoft.com/en-us/library/bb727085.aspx

You may want to take a look at the design IPD guide (Infrastructure Planning and Design) for AD – Download Details: IPD guide for Active Directory Domain Services – version 1.0
http://www.microsoft.com/en-us/download/details.aspx?id=732

Download the complete Infrastructure Planning and Design (IPD) Guide Series v2.0 including links for AD IPD, SCCM IPD, and more.
http://technet.microsoft.com/en-us/library/cc196387.aspx

Comments & Corrections are welcomed.

Ace Fekay

Nslookup suffixing behavior

Posted on February 17, 2013 by Ace Fekay

By Ace Fekay, MCT, MVP, MCSE 2012/Cloud, MCITP EA, MCTS Windows 2008/R2, Exchange 2007 & 2010, Exchange 2010 Enterprise Administrator, MCSE 2003/2000, MCSA Messaging 2003
Microsoft Certified Trainer
Microsoft MVP: Directory Services
Active Directory, Exchange and Windows Infrastructure Engineer

Original compilation: 2/17/2013

Prologue

Many IT folks who are not familiar with nslookup’s suffixing behavior in some cases may believe it’s a DNS issue. Nope, it’s not a DNS issue, rather a combination of nslookup’s suffixing behavior, which DNS server nslookup is using, Forwarders if configured, and the operating system’s Search Suffixes.

NSLOOKUP and requiring a trailing dot

Keep in mind, nslookup’s resolver service has its own built-in resolver service and is totally *independent* of the operating system’s client side resolver algorithm, (although it will use the machine’s suffixes to devolve names), and will behave differently than if you were to say ping a host by single name.

When using nslookup, you need to fully qualify the name (querying an FQDN), instead of a single name, then you must supply a trailing dot with the query.

If not, it will append the current context, that is the suffix(es) configured on the machine, which it will suffix each one in the order they are configured.

If you want to use a better tool for nameserver queries, I suggest to use DIG. DIG is downloadable as part of ISC’s BIND DNS server. You can download BIND for free from https://www.isc.org/wordpress/. Expand the files into a folder, and the tools will be available for use. No, this doesn’t mean you have to install the BIND DNS server service, I’m just suggesting to download and use the utilities in the folder. Matter of fact, BIND also has its own version of nslookup that some say works better than Microsoft’s nslookup, but I haven’t found that true. I’ve found DIG very beneficial when trying to troubleshoot DNS issues.

Additional nslookup information

Here are some links explaining nslookup’s behavior. The first one is a doc that explains more of this in greater detail. This doc actually was compiled from KB200525, the second link, which is also mentioned in the Microsoft Official Curriculum Course# 688, “Using TCP/IP,” Courseware.

Using NSlookup (File Format: Microsoft Word) – “Nslookup will always devolve the name from the current context. If you fail to fully qualify a name query (that is, use trailing dot), the query will be …; “
http://mcse.villanova.edu/Courses/688/documents/Using%20NSlookup.doc

Using NSlookup.exe
http://support.microsoft.com/?id=200525

Using NSlookup – (Microsoft Word Doc)
”Nslookup will always devolve the name from the current context. If you fail to fully qualify a name query (that is, use trailing dot), the query will be … “
http://mcse.villanova.edu/Courses/688/documents/Using%20NSlookup.doc

Nslookup, Sep 28, 2007 … This applies when the set and the lookup request contain at least one period, but do not end with a trailing period. Nslookup /set srchlist …
http://technet.microsoft.com/en-us/library/cc725991(WS.10).aspx

As the last link suggests, you can run nslookup with the /set srchlist, such as nslookup /set srchlist to set your own search lists that changes the default search suffix nslookup uses that it grabs from the operating system’s Search Suffixes. You can also set it in interactive mode by the following and leaving it blank to remove any search suffixes it’s pulling from the machine:

nslookup
> set srchlist

Will removing the Primary DNS Suffix affect AD functionality?

Yes and No. Yes if you remove the Primary DNS Suffix, which the default search list comes from and the machine uses in such cases as DirectSMB connectivity, among other things. And no, nslookup’s requirement of using a dot doesn’t affect or indicate any issues with AD, it’s just an nslookup thing.

In summary:

No, it’s not something that’s saying there is a DNS problem. To determine if you have a DNS problem, I suggest to use nslookup querying FQDNs with a trailing dot, or better, download and use DIG.

Further, you will need to use the trailing dot (a period) unless you remove the search suffix. You can also remove the suffix from the machine, and it will work without a trailing dot. But the search suffix is derived from the Primary DNS Suffix, which is set by the domain it’s joined to. You can remove it in the registry and not touch the Primary DNS Suffix.

You can also uncheck the computer’s client side resolver behavior, as shown in this screenshot (https://utgkjq.sn2.livefilestore.com/y1ppjK9K5o-JVAQJqWMjf9NSpoI9kTGnkjX_q5PGS3whQEFD-TPNXHMC0PU8rKjKt3AKPD5kuN0k9MyqK2I2sXd0mD2DSiTFiF0/DNS%20-%20Stop%20Suffix%20from%20Appending.jpg?psid=1).

Additional links to read on this subject:

Thread: “Weird NSLOOKUP results” 6/10/2010
http://social.technet.microsoft.com/Forums/sk/winserverNIS/thread/8f29df1a-46dc-4b3b-946c-528b10f7223e

Windows Appending Domain Suffix To All Lookups
http://serverfault.com/questions/74067/windows-appending-domain-suffix-to-all-lookups

Thread: “DNS server strange behavior” 2/9/2013
http://social.technet.microsoft.com/Forums/en-US/winserverNIS/thread/e3c9bc21-5037-4974-9329-fb86cf670494/

It’s just something to keep in mind when using nslookup.

I hope you find this info helpful.

Ace Fekay

Revisions

Prelude

AD Integrated Zones AD Database Storage Locations

The Active Directory Data Store (the AD database):

Ok, Now the DNS Basics:

Active directory Integrated Zones changes this a bit:

Duplicate or Conflicting zones?

Primary Standard Zone, Secondary Standard Zones & Zone Transfers

Do I need Zone transfers Allowed for AD Integrated Zones if I do not have Secondaries Zones?

Rotating SOA

References

Background:

Before I performed a test delete in my lab

Delete VAN-EX3

Trying to find the deleted object in the Recycle Bin using LDP

Recreating VAN-EX3 in the Exchange Organization in the Configuration Container

Point of the story: Be careful what you do in ADSI Edit.

Preface

This requires the IIS HTTP Redirect feature installed under Web Role Services

Steps to install the HTTP Redirect Feature:

Steps to configure OWA Redirect in Exchange 2010 and 2013:

Exchange 2003 & 2007 OWA Redirect

References:

If you want to use Brian Desmond’s which works perfectly, too, and I’ve been using it for over two years without a hitch, here it is:

Microsoft’s KB on OWA Redirect:

Other related links, just to get an idea what others have suggested, but I have not tried, so I can’t comment on them. You can try them at your own risk:

Comments, corrections, concerns, and suggestions are all welcomed!

Summary

Full explanation:

What will stop AD SRV registration:

Suggestions, Comments, Corrections are welcomed.

Preamble:

Preferably install at least one server OS on each subnet:

Third Party Devices Participating in the Browser Service

Browse List Propagation:

When to Troubleshoot

Prepare to Troubleshoot:

Firewall blocks – Test it with PortQry

Multihomed DCs:

Troubleshooting Steps:

Reference:

Comments, corrections and suggestions are welcomed.

Ace Fekay

First come up with an IP Range

Procedure (steps are not in stone)

Do Multiple Internal Subnets exist?

Comments, corrections and suggestions are welcomed.

Ace here again. Yea, I had to post a blog about this because many people ask, why do you want that? Just for the IP address??

Good question.

Let’s take a look at each value in an ipconfig /all

C:\>ipconfig /all

Windows IP Configuration

Host Name . . . . . . . . . . . . : company-dc-01

Primary Dns Suffix . . . . . . . : company.com

IP Routing Enabled. . . . . . . . : No

WINS Proxy Enabled. . . . . . . . : No

DNS Suffix Search List. . . . . . : company.com

Ethernet adapter Team 1:

Connection-specific DNS Suffix . :

Description . . . . . . . . . . . : BASP Virtual Adapter

Physical Address. . . . . . . . . : 00-18-8B-47-F0-D1

DHCP Enabled. . . . . . . . . . . : No

IP address, mask and subnet

DNS Servers . . . . . . . . . . . : 192.168.80.5 192.168.80.10

Primary WINS Server . . . . . . . : 192.168.80.10

NetBIOS over Tcpip. . . . . . . . : Enabled

Do you need NetBIOS? That Depends …

Quick Brief on NetBIOS and Those Noisy Broadcasts

Joining a machine to the domain.

Network and Printer Browsing

WINS

Legacy Apps Require NetBIOS

Exchange 2000/2003 Need NetBIOS

Search Suffixes

Suggestions, Corrections, & Comments are welcomed.

Preface

AD Sites

What are AD Sites?

What are AD Sites for?

Why can’t I create an AD Site without a DC in the Site?

DNS Servers . . . . . . . . . . . : 192.168.80.5
192.168.80.10