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November 9, 2016


RDS Health Monitor in F5 for Windows Server 2016

When rolling out new servers for Remote Desktop Services in Windows Server 2016, that are load balanced with F5 (Connection Broker servers specifically), I found that the Send/Receive strings used for the Health Monitors in F5 that we used for Windows Server 2012 R2 did not work in Windows Server 2016. After diving into some diagnostics logs, it looks like the response string has changed in Windows Server 2016. 

Here are the Send/Receive strings for both the old 20012 R2 and the new 2016 that worked for me:

Send String: \x03\x00\x00\x13\x0E\xE0\x00\x00\x00\x00\x00\x01\x00\x08\x00\x0b\x00\x00\x00
Receive String (2012 R2): \x03\x00\x00\x13\x0E\xD0\x00\x00\x12\x34\x00\x02\x0f\x08\x00\x08\x00\x00\x00
Receive String (2016): \x03\x00\x00\x13\x0e\xd0\x00\x00\x124\x00\x02\x1f\x08\x00\x08\x00\x00\x00

Read more from F5, Microsoft, RDS
3 Comments Post a comment
  1. filip lenaerts
    Nov 27 2016

    are bytes 9 and 10 in the RECV string of 2016 correct?


    according to ITU-T rec X.224 these should be two bytes, while \x124 is too large. The fields indicate the SRC refernce of the response PDU. Any other versoin of windows had here \x12\x34 (which of course doesn’t mean anything). Could you have meant \x12\x04 instead?


    • Brent
      Nov 29 2016

      Hey, yeah I thought it seemed odd too, but x124 is correct (for what has been working). I just copied and pasted the response from the F5 debug logs for the Health Monitor. I am not sure why it looks like this, but it’s the only RECV string I have been able to get to work with 2016.

  2. Al
    Jan 21 2020

    Do you know the Send\Receive strings for Windows Server 2019?


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