250 Hello - Random Musings on Security and Exchange

2

Exchange Managed Availability Error – OutlookRpcSelfTestProbe

Posted on 30th November 2020 by Rhoderick Milne [MSFT]

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”

1

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

Posted on 27th November 2020 by Rhoderick Milne [MSFT]

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

… Read the rest

3

A Tale of Two Certificates–SHA1 Certificate Created During Exchange 2016 Installation

Posted on 23rd November 2020 by Rhoderick Milne [MSFT]

The security space is constantly evolving, and while a lot of the recent work has been on moving to TLS 1.2, a previous focus in the industry was to stop issuing SHA1 certificates and transition to SHA2 based certificates. As a result, many will run security scans to review the presence of installed certificates and their properties. In one such engagement, the security team noted their displeas… Read the rest “A Tale of Two Certificates–SHA1 Certificate Created During Exchange 2016 Installation”

2

Exchange Setup – Certificate Is Expired – Part Deux

Posted on 19th November 2020 by Rhoderick Milne [MSFT]

Previously I managed to break one of my labs when replicating a customer situation and then had to fix it as noted in this post from 2017.

This time around though I really raised my game, and instead of one certificate being expired, all of them were. Yup every cert was toast. Trying to install the Exchange CU to update to the latest build did not go well at all. As you see below, all of the cer… Read the rest “Exchange Setup – Certificate Is Expired – Part Deux”

0

Unresolved RID 526 and 527 After ADPrep

Posted on 18th November 2020 by Rhoderick Milne [MSFT]

After preparing AD and installing the first Windows Server 2019 DC into an existing AD environment, it was noted that there were unresolved SIDs listed at the root of the domain. This was corelated to the AD 2019 upgrade as permissions had been audited and cleaned up prior due to previous issues in the environment. Previously all DCs were Windows Server 2012 R2 with all updates installed.

After r… Read the rest “Unresolved RID 526 and 527 After ADPrep”

0

Low Exchange Disk Space Monitors

Posted on 16th November 2020 by Rhoderick Milne [MSFT]

Exchange 2013 introduced us to the concept of Managed Availability. This reduced the reliance on external entities such as System Center Operations Manager (SCOM) or other 3rd party monitoring tools. Exchange became self aware, started to monitor itself and even perform certain recovery actions.

As an administrator we can review output of some of these monitoring actions using Exchange Management… Read the rest “Low Exchange Disk Space Monitors”

3

Unable To Install PowerShell Modules – Unable To Download From URI Error

Posted on 10th November 2020 by Rhoderick Milne [MSFT]

When you try to install a PowerShell module or connect to the PowerShell Repository you may get the below error messages:

WARNING: Unable to download from URI 'https://go.microsoft.com/fwlink/?LinkID=627338&clcid=0x409' to ''.
WARNING: Unable to download the list of available providers. Check your internet connection.

For make most glorious benefit engine of search:

PackageManagement\Install-Packag… Read the rest “Unable To Install PowerShell Modules – Unable To Download From URI Error”

4

Microsoft Teams High CPU – Using Hardware Acceleration with the Microsoft Teams Client To Lower CPU Load

Posted on 9th November 2020 by Rhoderick Milne [MSFT]

One of the benefits of Windows as a service is that we receive constant updates, security enhancements and additions to the OS. One of the new features in the 2004 build was the introduction of hardware accelerated GPU scheduling. For details on this new feature and some background on how the Windows Display Driver Model has evolved please read this excellent article.

In this post I will post my … Read the rest “Microsoft Teams High CPU – Using Hardware Acceleration with the Microsoft Teams Client To Lower CPU Load”

0

Exchange HCW Detects “Wrong” Version

Posted on 2nd November 2020 by Rhoderick Milne [MSFT]

When running Exchange setup or the Exchange Hybrid Configuration Wizard (HCW), I always recommend looking at the version information that is shown on screen. This is part of the gross error check to make sure that the correct version is being used.

This habit is one of the recommendations made in the Mistakes to Avoid Installing Exchange CU post.

Sometime you still may see something that surprises yo… Read the rest “Exchange HCW Detects “Wrong” Version”

0

AD FS Extranet Smart Account Lockout Protection

Posted on 27th October 2020 by Rhoderick Milne [MSFT]

Windows Server 2012 R2 AD FS added the Extranet Account Lockout protection feature. The intent of Extranet Account Lockout protection is to add an additional feature to password authentication which traverses Web Application Proxy (WAP). Note that the feature is not available for authentication directly targeting AD FS. The reason for this is that the Extranet Account Lockout protection was des… Read the rest “AD FS Extranet Smart Account Lockout Protection”