Bending an F5…

I was recently tasked with implementing an Exchange 2010 environment fronted by an F5 load balancer, sounds great right. One hitch the F5 was running version 10.2.0 and all over F5’s website and deployment guide they tell you that 10.2.1 is the minimum version for publishing Exchange 2010.

What does this really mean? From version 10 F5 have included Application Templates for various applications basically giving you a wizard for the otherwise very complicated configuration. In 10.2.0 the application template is missing a few vital components and contains a few errors, for various reasons the client I was working with couldn’t update so we had to try and make it work.


  • Follow the pdf to the letter, I highly recommend using the provided info sheets.
  • You can only run the template once for all your services, ie you can’t fill in Outlook anywhere and then go back and add ActiveSync (On a shared IP at least) so make sure you do them all at once.
  • Auto discover is missing from the template, you will need to manually create the pool and monitor as per the appendix tables on page 68.
  • Ensure you complete all the modifications to the template, page 22. Take note of the multiple monitor accounts.
  • Beware the I-Rule on page 75, this rule is the bread and butter of how the F5 separates the CAS services if you are balancing them on a shared address. The URL’s included eg  “/microsoft-server-activesync” are case sensitive and incorrect in the I-Rule provided. This took us 2 full days to solve. Make sure they match your Exchange URL’s exactly.

If this helps one person past the same situation I’ll be a happy man, a week trying to get this F5 working and no content on the web makes for frustrating times.


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