Exchange Center

ENow Software's Exchange blog built by Microsoft MVPs for IT/Sys Admins.

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Exchange 2013 on Windows Server 2012: Multi IP addresses, a single NIC

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Dominik Hoefling MVP

Many people want to use multiple IP addresses on a single NIC interface with Exchange 2013 and Windows Server 2012. There are several reasons for this multi-homed IP configuration, such as various receive connectors for diverse applications (fax, SharePoint, gateways, etc.), or for an additional IIS website, amongst other things.

The behavior that changed since Windows Server 2008 is that the source IP address on a NIC will always be the lowest numerical IP address. The challenge for every Exchange administrator is to configure the correct firewall settings for the appropriate IP address. Lets make an example:

You install the the first Exchange 2013 server in your environment with the „primary“ IP address of Afterwards you decide to add an additional IP address to your MAPI network adapter, such as for a further receive connector. The secondary IP address would be No you have two issues:

  • The server registered two DNS names for the same server
  • The server is now sending all outbound traffic from, because 100 is lower than 200.

Let's go a bit deeper and explain the “weak host model“ and the “strong host model“ for multi-homed servers and how they choose the source IP address selection.

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Computer Configuration

Configuring Anti-Affinity in Failover Clusters

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Michel de Rooij

Many customers nowadays are running a virtualized Exchange environment, utilizing Database Availability Groups, load balanced Client Access Servers and the works. However, I also see environments where it is up to the Hypervisor of choice on the hosting of virtual machines after a (planned) fail-over. This goes for Exchange servers, but also for redundant infrastructure components like Domain Controllers or Lync Front-End servers for example.

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Exchange 2013 Lab Tutorial: Part 7- Setting up DAG Databases and SSL

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Andy Grogan


To recap – the previous parts (should you wish to read them, refresh or catch up) can be found below:

Part 1

We established our domain design, covered how to provision the Domain Controller for the LAB in Hyper-V and then how to install Windows Server 2012 on the Domain Controller.

Part 2

We went through the process of installing Active Directory Domain Services on the LAB domain controller using PowerShell.

Part 3

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Windows Installation

Removing KB2667402 Before Installing Windows 2008 R2 Service Pack 1

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Andy Grogan

I have been working on a large Exchange 2010 upgrade to Service Pack 2. The Exchange environment that I have been working within works well, but it has not had a lot of TLC in a while, and aside from the upgrade to Service Pack 2 for Exchange, I also needed to perform an upgrade to Service Pack 1 of the Windows 2008 R2 O/S.

Now, this Exchange infrastructure has a number of nodes spread out over the UK, therefore much of the work has needed to be done remotely via RDP. Initially, the work was going very well – prepped the first Exchange DAG node for the Operating System update via the “StartDAGServerMaintenance.ps1” script and then executed the Windows 2008 R2 Service Pack 1 installation process.

The service pack itself went well – right up until the point where I needed to reboot when the processes had finished. After the reboot had completed – I found that I could no longer RDP to the machine (which was based in Oxford which is about 70 miles from me so I was not going to get there in a hurry). I could get the RDP client to initialise the connection and perform a logon, but at the point where the session was preparing the User Desktop it would disconnect the session!

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