Tag Archives: Load Balancing

SMTP load balancing with F5 LTM

In my previous blog I explained how to configure the F5 LTM for use with Exchange 2010 CAS servers. To do this properly it is recommended to use a template (iApp) because of the amount of work (and thus complexity).

Load balancing SMTP is much easier. The only things that need to be configured are:

  • Service Monitor for monitoring the SMTP service on the Exchange 2010 Hub Transport Servers;
  • A Pool containing the Exchange 2010 Hub Transport servers;
  • A VIP for the SMTP service with a listener on the public network.

To create a new Service Monitor select the Local Traffic and click the + symbol next to monitors. Give the new monitor a name like SMTP_Monitor and if needed adjust the service health monitoring interval. Continue reading SMTP load balancing with F5 LTM

Load Balancing Exchange 2010 with F5 LTM

In a earlier blogpost on load balancing Exchange 2010 I explained how to achieve this with a Kemp Loadmaster. In this blogpost I’d like to demonstrate how to configure this with an F5 Local Traffic Manager (LTM). This is actually part I of what I’ve demo’ d in the MEC 2012.

The configuration looks like this. There are two multi-role servers configured with a Database Availability Group (DAG). There’s a File Share Witness (FSW) configured on server FS01. The F5 itself is installed in a two arm configuration, so the VIP for the clients is on a different subnet then the Exchange Server.

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Continue reading Load Balancing Exchange 2010 with F5 LTM

Load balancing Exchange 2010 (part II)

In my previous post I discussed Exchange 2010 load balancing principles briefly (I need to leave some additional stuff for my MEC presentation) and how to setup a Kemp LoadMaster in a single-arm configuration. In this 2nd (and final) blog post I’ll show you how to configure Virtual Services for OWA 2010 and MAPI (Outlook clients).

Create a new Virtual Service for OWA

To create a new Virtual Service expand the Virtual Services and click Add New to open the wizard and fill in the necessary options like the IP Address of the new virtual service, the accompanying port number and give the service a nickname. In the Use Template option you can select a predefined template for the service. The advantage of using a template is of course that all options are filled in by Kemp, optimized specifically for the LoadMaster. Since we’re creating an OWA service select the Exchange HTTPS Offloaded template and click the Add this Virtual Service button.

In this example the Client Access Servers are configured with SSL offloading. The clients connect to the LoadMaster using SSL, the LoadMaster in turn connects just on port 80. For more information on how to configure SSL offloading in Exchange Server 2010 please check this blog post: http://www.jaapwesselius.com/2012/06/10/ssl-offloading-with-powershell/

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Figure 1. Select a preconfigured template to use when creating a new Virtual Service.

Continue reading Load balancing Exchange 2010 (part II)

Load balancing Exchange 2010 (Part I)

During TechEd 2010 in Berlin Ross Smith IV from Microsoft suddenly announced that Microsoft recommends using a hardware load balancer for Exchange Server 2010 instead of using Windows Network Load Balancing. You can check the presentation online on Channel9: http://channel9.msdn.com/Events/TechEd/Europe/2010/UNC311.

NLB has some known issues when it comes to Exchange Server 2010 like scalability issues, lack of service awareness, a full reconnect of all clients when adding or removing a new NLB member and only the option of Source IP for persistence.

Continue reading Load balancing Exchange 2010 (Part I)