VMware vCenter – “Exception in invoking authentication handler User password expired”

An appliance that was deployed over 90 days old with no changes made to the default settings. When attempting to logon to the VAMI console of the appliance i.e. https://vcenter.domain.com:5480 you get the message: “Exception in invoking authentication handler User password expired”. To resolve this you need to reset the password, then set it not … Read more

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 … Read more

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 … Read more

SSLScan for Website SSL Diagnostics

Had an issue where we had a client that couldn’t access a particular site, in this case we wanted to determine what encryption ciphers a particular website was offering on its HTTPS server, SSLScan which is a Linux tool available on Ubuntu and other distributions can help, for example:

How to Check Domain NS Glue Records (using DIG)

The resolution of a DNS FQDN requires a number of servers to be queried, typically your machine (or a DNS resolver – on your behalf) will query the root DNS (name) servers, these will then return the (registrar) name servers that serve the TLD (top level domain) e.g. .com, .co.uk etc. for your domain, these … Read more

DNSSEC Explained (with AWS Route53 Hosted Zone Example)

DNS name resolution is essential to modern connectivity. The ability for hosts to be able to quickly and reliably resolve DNS domain names (e.g. www.google.com) to their IP address equivalents (e.g. 216.58.204.68 or 2a00:1450:4009:827::2004) to connect and consume services ensures consistent and performant network flows. Due to the essential nature of DNS, DNSSEC is an addition … Read more

AWS Route53 – Creating and Using a Hosted Zone

AWS Route53 provides DNS Resolution (and DNS Registrar) services. You can use Route53 to register a domain, host the zone file and provide DNS resolution, alternatively, you can have the domain registered elsewhere, but then use Route53 to host the zone file and provide DNS resolution. There are some different options here, Route53 ties nicely … Read more