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Forum Discussion

Gerald_Cheminan's avatar
Gerald_Cheminan
Icon for Nimbostratus rankNimbostratus
Jan 14, 2016

Lync Server 2013 HLB

Hi all, At first I describe my environnement :   AD Local domain = internal.ad Public domain = SMTP domain = SIP domain = publicdomain.com Lync Server Enterprise Pool PoolEE.internal.ad FE01.i...
application delivery
BIG-IP
iApps
mikeshimkus_111's avatar
mikeshimkus_111
Historic F5 Account
Jan 19, 2016

That is correct, BIG-IP will load balance the first request to the Front End servers, but after that the clients will communicate directly to them.

 

  • Gerald_Cheminan's avatar
    Gerald_Cheminan
    Icon for Nimbostratus rankNimbostratus
    Jan 20, 2016
    Hi Mickael, Again thank a lot for your quick and quality answer. To complete my questions, I find very good articles by Thomas Poett about HLB, certificates.. I wanted to share with you and confirm your analysis. https://gallery.technet.microsoft.com/office/Lync-2013-internal-3ac7ddfb https://gallery.technet.microsoft.com/office/HLB-and-DNS-Load-Balancing-3cb98ec4 Have a nice year 2016 ! !
  • Sohaib_Atta_251's avatar
    Sohaib_Atta_251
    Oct 30, 2016

    Hi mikeshimkus,

     

    Why is the first request directed to the FrontEnd VS and the subsequent client communication directly with with front end servers? Why aren't the subsequent requests directed towards the F5 FrontEnd Virtual Server and based on persistence records forwarded to the Actual front end server? Shouldn't all communication take place via F5?

     

    If this it the normal working behavior can you please direct me to exact resource of documents which specifies this. The point is if F5 is also acting for the first request only and subsequent connections are directly to the FrontEnd Servers it's more or less similar to DNS load balancing.

     

  • mikeshimkus_111's avatar
    mikeshimkus_111
    Historic F5 Account
    Oct 31, 2016

    Sohaib, I am unable to locate any Microsoft documentation about this, but both HLB and DNS LB work similarly. When you resolve the Front End server's IP via DNS or connect to it via the VIP, it returns you a list of pool members which the client then uses to connect (and caches for future reference).

     

    The only real difference here is that unlike DNS, the BIG-IP will NEVER forward the initial request to a Front End server that is not responding, which should improve response time and eliminate the need for manual updating of DNS records.

     

    Hardware load balancing is only required for Lync/Skype web services, BTW.