Dell : How to install a custom issued SSL certificate on iDRAC

If you already have a certificate generated by a certificate authority (or maybe a wildcard certificate), you can use the following procedure to configure it on your iDRAC, so you can get rid of the browser security warning. We will use the iDRAC “racadm” command line utility (if you do not have it already, you… Read More »

VMware : Time on VCSA is out of sync with external PSC

This issue appear to be banal, but actually consumed precious (lost) time of my day deploying a vCenter Server Appliance on an external Platform Service controller, version 6.5. At the “Install – Stage 2: Set Up vCenter Server Appliance”, you are asked for Single Sign-On infos of the PSC appliance. Clicking next, you may encounter… Read More »

JunOS : Configuring the QSFP+ uplink ports on EX4300

By default, all QSFP+ ports on the EX4300 chassis are configured as virtual chassis ports (vcp). VC minimal (recommended) requirement is two ports, meaning that two out of the four ports can be used as regular 40 Gbps interfaces and/or for uplink purpose. Let’s assume we want to use the port #0 and 1 as… Read More »

MacOS : Unable to negotiate with 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 port 22: no matching cipher found. Their offer: aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,arcfour,aes192-cbc,aes256-cbc, 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 »

Linux : How to show connected client of NFS export on the server?

Here is how to quickly show the connected clients to a NFS server. It might be useful to know before rebooting the server! On the server, execute the following command (replace <> with the NFS server IP address) :

Example :

You should see a similar output : tcp 0 0… 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) :

Example :

Change Group… Read More »

ScreenOS : SSL error accessing the WebUI

If you are using the WebUI to manage your Juniper SSG / ScreenOS device, you probably encountered the following error accessing the page lately : ERR_SSL_VERSION_OR_CIPHER_MISMATCH If you use a browser that allow SSLv3, you will be able to access the device. However as we all know the weakness of this protocol, it isn’t ideal… Read More »