You may at some point end up with virtual machines marked with “Invalid” status in the vSphere Web client or vCenter. You will also notice that the contextual menu does not show up the usual options (mostly everything is greyed out) and more importantly, the “Unregister” or “Delete” options are unfortunately unavailable. Chill out, there… Read More »
Windows Firewall can be configured from the GUI (by using firewall.cpl UI console) and also using the command line. This quick tutorial will cover how to manipulate the rules from CLI to open, block a port and delete a rule. In a nutshell, here is the command sample: netsh advfirewall firewall add rule name=”<DESCRIPTION>” dir=in… Read More »
While adding a new security zone on your SRX firewall, you may encountered the following error while committing your changes: [edit security zones security-zone VLAN1] ‘interfaces irb.1’ Interface irb.1 must be configured under interfaces error: configuration check-out failed This is a common mistake where the irb interface configuration was forgotten. For those unfamiliar with the… Read More »
cPanel AutoSSL feature is great, but sometime can run into issues. Once in a while, you may have some certificate requests pending forever without any particular reason. This usually can be fixed by clearing the queue and force AutoSSL to run for the stuck domain again. 1. Move the AutoSSL database file under a different… Read More »
You may have experienced the following behavior while trying to upgrade your vCenter Server Appliance (VCSA) to 6.7.x – after submitting the IP and credentials information of the current vCenter and host, the wizard end up with error without any details. However, after downloading the log (there is a link within the red error bubble… Read More »
If you have a Gigabyte Z390 Designare motherboard, you might be wondering how to enable Secure Boot in order to meet the TPM2 Windows 11 requirement. Browsed every section of the BIOS and didn’t found it? Most likely you have “CSM Support” option enabled. (Compatibility Support Module (CSM) is a feature of the UEFI firmware… Read More »
If you have a HPE Comware switch stack, you may at some point need to access the CLI of a particular unit member in the stack for troubleshooting purpose. When running a switch stack, when accessing the CLI, the commands will always perform actions on the unit running as “master”, so this easy tutorial will… Read More »
In this article we will cover the procedure to reset a Cisco Catalyst to factory default settings. This will wipe out the current configuration written in flash and also the VLan database file as well. 1. Connect the switch serial console port to a computer and open up a terminal so you can see the… Read More »
You may have noticed that the OSSEC Web Interface stopped working (as of today on a new installation) or after updating PHP on your server. Looking at the logs, you most likely found a similar entry: PHP Fatal error: Uncaught Error: Call to undefined function split() in /var/www/html/ossec/lib/os_lib_agent.php:111\nStack trace:\n#0 /var/www/html/ossec/site/main.php(33): os_getagents(Array)\n#1 /var/www/html/ossec/index.php(126): include(‘/var/www/html/o…’)\n#2 {main}\n thrown… Read More »
Recently, without any change, I noticed that some cPanel servers stop sending email and return the following error: 550-Please turn on SMTP Authentication in your mail client. 550-hostname.domain.tld [0.0.0.0]:00000 is not permitted to relay 550 through this server without authentication. What is really puzzling in that case is that this message showed up even though… Read More »