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QuickTip – Query Block Mode

Exchange 2010 SP1 introduced the concept of block mode or granular replication.  This minimised the time taken for transactions on the active node to be replicated to passive nodes.  Since the feature is enabled by default and is self-managing, there is a good chance that you are benefiting from it without being fully aware of it.

See also understanding High Availability and Site Resilience

If you d… Read the rest “QuickTip – Query Block Mode”

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Exchange 2016 CU20 Released

Exchange 2016 CU20 has been released to the Microsoft download centre!  Exchange 2016 has a different servicing strategy than Exchange 2007/2010 and utilises Cumulative Updates (CUs) rather than the Rollup Updates (RU/UR) which were used previously.    CUs are a complete installation of Exchange 2016 and can be used to install a fresh server or to update a previously installed one. Exchange 2013 h… Read the rest “Exchange 2016 CU20 Released”

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Collected Links For Hafnium – March 2021 Exchange Security Issue

The below are a series of links, tips and some very brief thoughts on Hafnium.  I will purposefully not include the content of the other locations as it is changing so rapidly, and there is no way to ensure that it would be updated here in a timely fashion.

 

 

If you read nothing else, please ensure that you install the update from an elevated CMD prompt if you are manually installing. 

FaiRead the rest “Collected Links For Hafnium – March 2021 Exchange Security Issue”

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Out of Band Critical Exchange Security Updates–March 2021

Security updates were released today for Exchange 2010, 2013, 2016 and 2019.  Attacks were detected which leveraged these vulnerabilities, so an out of band set of updates was released

This a remote code execution on TCP 443 and is already being exploited as a 0-Day attacks against on-premises Exchange servers.

Microsoft strongly recommends installing this update immediately.  Internet facing serverRead the rest “Out of Band Critical Exchange Security Updates–March 2021”

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Exchange 2016 CU19 Released

Exchange 2016 CU19 has been released to the Microsoft download centre!  Exchange 2016 has a different servicing strategy than Exchange 2007/2010 and utilises Cumulative Updates (CUs) rather than the Rollup Updates (RU/UR) which were used previously.    CUs are a complete installation of Exchange 2016 and can be used to install a fresh server or to update a previously installed one. Exchange 2013 h… Read the rest “Exchange 2016 CU19 Released”

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Exchange December 2020 Security Updates

Please be aware that Exchange 2013, Exchange 2016  and Exchange 2019 security updates were released as part of the December 2020 patch Tuesday release.  The overall rating is critical, and the update resolves multiple issues.

Details for these, and previously released updates can be found in the Security Update Guide.  Also note that Exchange 2010 SP3 RU31 was also released.

 

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For all of th… Read the rest “Exchange December 2020 Security Updates”

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Exchange 2013 OnPremisesSmtpClientSubmission – Unhealthy After Disabling TLS 1.0 and TLS 1.1

After going through the steps to disable TLS 1.0 and TLS 1.1, it was noted that Managed Availability was not happy with one particular component in Exchange 2013.  This was the OnPremisesSmtpClientSubmission probe and the monitor which was associated to it.  The below is a reproduction of the customer environment.

For reference, you can review Protocols in TLS/SSL (Schannel SSP) for a listing of wh… Read the rest “Exchange 2013 OnPremisesSmtpClientSubmission – Unhealthy After Disabling TLS 1.0 and TLS 1.1”

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Exchange Managed Availability Broken With TLS 1.2 Changes

In most enterprise customers there is a segregation of duties between multiple teams.  This could be networking and desktop.  Or Windows Server platform and messaging.  It was the split in these roles, and especially a dearth of communication which led to this tale of woe with TLS 1.2 and Exchange.

The reasons for moving to TLS 1.2 and avoiding SSL2, SSL3, TLS 1.0 and TLS 1.1 should be well underst… Read the rest “Exchange Managed Availability Broken With TLS 1.2 Changes”

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Exchange Managed Availability Error – OutlookRpcSelfTestProbe

This case illustrates the "fun" with Managed Availability a particular customer had after making changes to their servers.  The servers were built back in 2014, and as such the default self signed certificates had expired and were previously replaced.  This is because the Exchange self signed certificates have a 5 year validity period.

It was noted that Managed Availability was not healthy in all r… Read the rest “Exchange Managed Availability Error – OutlookRpcSelfTestProbe”

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Unable To Add Server to DAG Enabled Computer Object With The Given Name Already Exists

Unable To Add Server to DAG Enabled Computer Object With The Given Name Already Exists

As we saw previously, Windows Server 2012 introduced some changes with regards to creating a Database Availability Group (DAG).  For example, you may have encountered this issue Add-DatabaseAvailabilityGroupServer – You Must Provide A Value For This Property.

The issue below is another example where the pre-work to create the underlying DAG computer network object (CNO) was not done fully.

Starting

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