Christos Polydorou

The trigger to write this article was a troubleshooting session with a client that had built an automation process to deploy Windows Server and RedHat Enterprise Linux virtual machines on Azure. One of the steps of the provisioning process was to join the machine to the IaaS Active Directory Domain that was deployed on Azure and for this, an Active Directory account was required. Following the least previlege principle, the account used in the automation processes to join machines to the domain was a plain account that could indeed perform this operation. After some successfull joins however, the process started encountering errors when trying to join machines to the domain. As it turns out, the architects and security engineers had missed the fact that plain Active Directory accounts have the ability to only join a specific number of machines to the domain. When the automation reached that number, the process started to fail. To further troubleshoot the issue, we tried to join t...

Whenever I'm called to setup or troubleshoot Citrix NetScaler performance issues, I try to bring Citrix InSight Center into the game. InSight Center is a Linux based Virtual Machine which gathers AppFlow performance data from the NetScaler thus helping with performance troubleshooting. I am not a fan of local user accounts on any system for many reasons, so I'll show you how to delegate the user authentication of the InSight Center to Active Directory. Let's start with logging on to the InSight Center using the default administrator account "nsroot" and navigating to the "Authentication" node under "System". Here we see all the available authentication methods supported: RADIUS, LDAP and TACACS. Since we want to delegate the authentication to Active Directory, we're interested in LDAP. Select the "LDAP" methods, and then click "Add" to add a server. Fill in the IP address of a domain controller (or a Load Bal...