Active Directory Read Only Domain Controller (RODC) – “there are currently no logon servers available to service the logon request”

We had an issue where our RODCs suddenly stopped authenticating users and also would not allow administrators to logon via RDP or locally via the console giving this message: “there are currently no logon servers available to service the logon request” Any downstream services that were trying to authenticate via LDAP or LDAPS also failed […]

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Query Message Tracking Logs on Microsoft Exchange using Powershell

You want to search your Microsoft Exchange message tracking logs to track an email, you can do this using a Powershell command (run from the Microsoft Exchange Powershell console), the below command will query all your Microsoft Exchange servers to find the tracking logs and then obtain all emails sent by the user “sender@domain.com” between […]

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Microsoft Exchange 2016 DAG Error Setting Witness Server and WitnessDirectory

We have a number of 2 node DAGs which provide our Microsoft Exchange 2016 service. Being a 2 node DAG a file share witness server is in place. We had a datacentre event that took out one of the nodes and the witness server, rendering the one of the DAGs unhealthy and a second in […]

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Microsoft Exchange 2016 – How to Fix Exchange DAG Witness Failed State

In certain situations the Exchange DAG witness can become a problem, this can occur during an upgrade or can happen if there is a network interruption. Although the DAG will continue to operate the witness is considered failed, which can cause odd behaviour in a failover scenario, as there is no quorum available for the […]

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Continuing Analysis and Resolution of NetApp and RC4 Issues Caused by (KB5019964) For CVE-2022-37967 and KB5021131 CVE-2022-37966

A long running issue, which I covered in my previous posts: https://geekmungus.co.uk/?p=3532 and https://geekmungus.co.uk/?p=3593, this should be taken as the current status of the problem and the resolution. Issue Following the patch: KB5021131 CVE-2022-37966, which was released November 8th 2022 we’ve continued to have some issues with Kerberos authentication to servers (devices) that use (and […]

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Calendar Publishing to Internet from Microsoft Exchange (2016+)

Microsoft Exchange provides the capability to allow publishing of user calendars to the Internet, this is different from calendar sharing (which is typically internal, i.e. within our organisation). These instructions explain how to enable publishing by policy and how to apply it your own user mailbox. Calendar Publishing Policy Configuration on Microsoft Exchange These steps […]

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