Category Archives: Operating Systems

MacOS : Unable to negotiate with 0.0.0.0 port 22: no matching cipher found

Having the following issue connecting to a device using SSH after upgrading to macOS High Sierra 10.13.2? Unable to negotiate with 0.0.0.0 port 22: no matching cipher found. Their offer: aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,arcfour,aes192-cbc,aes256-cbc,rijndael-cbc@lysator.liu.se This is an expected behavior if you attempt to connect to a legacy system or network device running older version of SSH. To workaround… Read More »

Windows : How to pause Windows 10 updates download

Since Windows 10, Microsoft made it harder for users to disable automatic updates and downloads. When triggered automatically, there is no function on the user interface to stop them, unfortunately. If you are running with the default settings, you might at some point end up working on your computer and noticed that your bandwidth was… Read More »

Linux : How to change User and Group ID

There might be some (rare) circumstances where you would like to change a UID or GID on Linux system. If you know what you are doing and the implication behind this change (see warning comment below), this can be achieved using the commands below. Change User ID (UID) : usermod -u <ID> username Example :… Read More »

Linux : Yum/rpm broken upgrading from CentOS/RHEL 7.3 to 7.4 (error: Failed to initialize NSS library)

You probably experienced the following issue, running “Yum update” on a RHEL 7.3 system : error: Failed to initialize NSS library There was a problem importing one of the Python modules required to run yum. The error leading to this problem was: cannot import name ts Please install a package which provides this module, or… Read More »

Windows : BSOD 0x0000007E (0xFFFFFFFFC0000005, 0xFFFFF880018C9836, 0xFFFFF880009A9008, 0xFFFFF880009A8860)

I had the luck of experiencing the following blue screen on a Windows Server 2008 R2 domain controller server at boot lately : *** STOP: 0x0000007E (0xFFFFFFFFC0000005, 0xFFFFF880018C9836, 0xFFFFF880009A9008, 0xFFFFF880009A8860) Related facts with this server : – Haven’t been rebooted since two years – Windows Updates haven’t been run for two years – Running minimalistic… Read More »

Linux : How to show interface IP address at boot on the console with CentOS/RHEL7?

Particularly useful when building appliances or when you ship pre-build systems to a remote location where technical knowledge of people at the remote site is limited, you can easily make the system “print” the IP acquired by DHCP or even the static assigned one to the system console login. You will need to create two… Read More »

Windows : Time synchornization

There might be a few situations where you need more flexibility than what the clock UI can provide. In that case, you will need some help from the command line and registry. To manually synchronize the clock with a time server using the command line : net time \\<ntp_server> /set /yes NOTE : Replace <ntp_server> with… Read More »

Linux : perl: warning: Setting locale failed

You probably noticed the following output on your console after logging to your newly installed CloudLinux server : perl: warning: Setting locale failed. perl: warning: Please check that your locale settings: LANGUAGE = (unset), LC_ALL = (unset), LC_CTYPE = “UTF-8”, LANG = “en_US.UTF-8” are supported and installed on your system. perl: warning: Falling back to… Read More »

Windows : The following error occurred attempting to join the domain “domain.tld”: The request is not supported.

Ending up with the following error trying to join a server or workstation to an existing Active Directory domain? The following error occurred attempting to join the domain “domain.tld”: The request is not supported. Additionally, if you have a look at the EventViewer, you can see the following log entries under the following logging facility… Read More »

Linux : fuser command not found on CentOS/RHEL 7

You may have encountered the following issue trying to run “fuser” command on CentOS/RHEL 7 : fuser: command not found Many system administrators turn to do minimalist installation with version 7, unfortunately this even cut some critical basic components such as “traceroute, ifconfig, fuser, etc.” which in my opinion should be a part of a… Read More »