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Thursday, March 15, 2018

ExMon - a tool to measure Exchange 2016 usage

Wednesday, March 14, 2018

Windows 2008 R2 TLS Poodle vulnerability

Install KB2655992 and reboot server

Exchange 2016 Prefered Architecture

Microsoft has designed a Prefered Architecture model (PA) which sounds more like Sci-fi for real world installation - companies want to use Virtualisation, PA talk about physical servers, companies want SAN, PA - DAS, etc.

Get more information here:

few more session dedicated to PA:

And the epic one:    realworld non-PA implementations.

Friday, January 26, 2018

Integration with Exchange Online breaks Skype for Business federation


if you follow this article to setup your  integration with Exchange online (for voicemail)

you may kill your sfb federation. If this is a case, please note a following specificity of SFB:

when you set up Edge, you will be confronted with a choice, where to set your DNS. You can set it to external DNS, such as  or your internal DNS.

If you select external, you might need to define some hosts file entry like for FrontEnd pool, etc. Not ideal, right?

then you select internal DNS. However once you run

New-CsHostingProvider -Identity UMonline-Enabled $True -EnabledSharedAddressSpace $True -HostsOCSUsers $False -ProxyFQDN "" -IsLocal $False -VerificationLevel UseSourceVerification

you cut all federation. This is due to the fact that after this powershell , the edge will try to look for it's own SRV _sipfederationtls._tcp   and because it is usually not defined internally, it will fail.

Solution is to check what is defined externally and in internal split DNS zone create exactly the same (SRV pointing to A record of to external public IP of edge access (SIP) interface. 

Tuesday, December 19, 2017

EWS dependency on Skype for Business Contacts folder in Exchange

FYI: EWS might depend on this folder and we have seen cases where SFB client had 15 minutes delay to recover EWS errors. You need to make sure that this folder exist or to disable it with policy. One of the ways to create this folder is to use Lync 2013 RTM client.