Microsoft

After deploying a new Microsoft Exchange organization with Exchange 2016, or after deploying a Microsoft Exchange 2016 into an existing organization, you might notice a strange behaviour regarding the Offline Address Books (OAB).

[PS] C:\Windows\system32>Get-OfflineAddressBook

Name                                    Versions                                AddressLists
---- -------- ------------
Standard-Offlineadressliste             {Version2, Version3, Version4}          {\Globale Standardadressliste}
Standard-Offlineadressliste (Ex2013)    {Version4}                              {\Globale Standardadressliste}

Huh?! Where does this Exchange 2013 OAB come from? As you can see in the cmdlet output, there’s no Exchange 2013 in this organization.

Another bug in Exchange 2016 CU2. The Role of a new receive connector is greyed out. You can select “Front-End-Transport”. This is a screenshot from a german Exchange 2016 CU2.

Solution

Use the Exchange Management Shell to create a new receive connector. Afterwards, you can modify it with the Exchange Control Panel (ECP).

[PS] C:\Windows\system32>New-Receiveconnector -Name "Client Frontend Dummy" -RemoteIPRange ("192.168.200.99") -TransportRo
le "FrontendTransport" -Bindings ("0.0.0.0:25") -usage "Custom" -Server "exchange1"

Identity                                Bindings                                Enabled
-------- -------- -------
EXCHANGE1\Client Frontend Dummy         {0.0.0.0:25}                            True

Microsoft has confirmed, that this is a bug in Exchange 2016 CU2.

Sometimes it’s necessary to have two DNS servers that are authoritative for the same DNS namespace. This is the case if you use the same namespace for your web site and your internal Active Directory domain, e.g. terlisten-consulting.de. Or that you have created the zone terlisten-consulting.de in your Windows DNS to point specific hosts to internal IP addresses. The DNS servers at your ISP would be authoritative, and the domain controllers of your Active Directory would also be authoritative for the same domain. The response to a query depends on which DNS server you ask. So what would happen if you try to resolve www.terlisten-consulting.de, and the internal DNS has no record for it?

As any other environment, my lab needs some maintenance from time to time. I use a Windows 2012 R2 VM with the Windows Server Update Service (WSUS) role to keep my Windows VMs up to date. Like many others, I was surprised by KB3148812 (Update enables ESD decryption provision in WSUS in Windows Server 2012 and Windows Server 2012 R2), which broke my WSUS. But the fix was easy: Uninstall KB3148812 and reboot the server. The WSUS product team published an artice about this known issue in their blog: Known Issues with KB3148812. In the meantime, Microsoft has published a new update, which supersedes KB3148812: KB3159706.

Last week, I was surprisingly booked by a customer who observed a problem in his network. Unfortunately, colleagues worked on this network some day before (moving servers, routers etc. to a new pair of HP 7509 new core switches).

It was quickly clear, that some of the clients have received the wrong DNS servers from the DHCP server. The environment is a bit unusual. The customer is running two Active Directory domains (root and sub domain) in a single layer 2 broadcast domain. This nothing unusual, but he is also running two DHCP servers in the same layer 2 broadcast domain. To get this working, the customer uses exclusion ranges and reservations. This guarantees, that the client receives the correct DHCP information.

A load balancer is an integral component of (nearly) every VMware Horizon View design. Not only to distribute the connections among a number of connection or security servers, but also to provide high availability in case of a connection or security server failure. Without a load balancer, connection attempts will fail, if a connection or security server isn’t available. Craig Kilborn wrote an excellent article about the different possible designs of load balancing. Craig highlighted Microsoft Network Load Balancing (NLB) as one of the possible ways to implement load balancing. Jason Langer also mentioned Microsoft NLB in his worth reading article “The Good, The Bad, and The Ugly of VMware View Load Balancing”.

Generating a certificate signing request (CSR) is the first step towards a signed certificate. The requests is generated with the applicants private key and consists of the public key, a name and optional attributes.

To generate a CSR, you can use tools like OpenSSL on a Linux box, or sometimes the application itself can generate a CSR. But if you have a Windows box, you don’t have OpenSSL by default. And it’s unhandy to install something just for a single CSR. You can use certreq.exe to create a CSR. This tool is mostly unknown, but it’s included since Server 2000. The syntax slightly differs between the version, so I focus on the version that is shipped with Server 2008/ Windows Vista and newer.

Some day ago, I installed a new Exchange 2013 CU11 for some test ins my lab. Nothing fancy, just a single server deployment on a Windows Server 2012 R2 VM. I deployed this Windows Server from a template, which was updated with the latest Windows Patches and WMF some days ago. The Exchange setup went smooth. I updated the SSL certificates and the internal and external URLs for the virtual directories. Then I started the Exchange Management Shell (EMS), to update the Autodiscover URL in the service connection point (SCP) of the Active Directory.

Shrinking a big database on a Microsoft SQL Server can take some time. And it’s one of those tasks, where you wont get a status until it’s finished. I really hate this… But this small T-SQL query can help:

SELECT 
    percent_complete, 
    dateadd(second,estimated_completion_time/ 1000, getdate()) as est_completion_time
FROM 
    sys.dm_exec_requests
WHERE
    command = 'DbccFilesCompact'

Simply open a new query windows, paste the query into the query windows and execute the query. The query outputs the progress in percent and the estimated completion time.

In January 2014 I wrote a blog post about network flooding because of Windows NLB clusters in unicast mode. Yesterday, Windows NLB, HP switches and I met again.

After moving a customers core network from HP 5400zl switches to two IRF stacks with HP 7506 switches, multiple Windows NLB clusters stopped working. Because the Windows NLB used multicast operation mode, it was instantly clear that the switches were the problem.

The explanation is easy: By default, a Comware based switch does not learn multicast MAC addresses. And because of this, the switch does not add them to the ARP table. And you can’t add static multicast MAC address entries. You have to disable the ARP entry check.