Automatically force log off and terminate disconnected RDP sessions to free up system resources.

I’m working with a situation where all of the computers in a computer lab are actually zero-clients connecting to a dedicated Windows 7 VM on a server cluster. This environment has its complexities, and I’m working to improve the performance. That being said, I would get frequent notices from the Instructor that the computers would be running slow. Rebooting the VMs would fix that, but it appeared that was just a Band-Aid. I noticed that each VM would hold on to the disconnected RDP sessions and continue to consume resources in the background.…

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Check if your accounts have been compromised in an online data breach

With all of the recent data breaches, online security is (and has been) becoming a growing concern. If you aren’t aware, hundreds of major breaches have been publicized, and who knows how many smaller breaches are going unnoticed each day? With the “have I been pwned” website, you can both view a list of pwned websites (websites which have been breached and data compromised) and also check your e-mail addresses and online usernames to see if they were included in any of those breaches. What if I’ve been pwned?! How you use…

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Secure your Sophos Network: Use Network Groups for Trusted Remote Hosts.

My primary concern lately as my internet presence has grown has been in the general realm of security. How do I know that no one is accessing my port-forwarded server? How do I know that no one is logging into my router? […] An easy answer to this has always been limiting inbound connections to trusted hosts; But that’s not always an easy solution. Most consumer routers don’t even support this (correct me if i’m wrong) and in most firewall applications it can be cumbersome to append and manage trusted…

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How to fix Sophos UTM 9.4 install.tar wasn’t found on the installation media

I’ve been deploying Sophos Virtual Appliances recently and so I was presented with a bit of a challenge when the install was failing on physical hardware. Error: install.tar wasn’t found on the installation media. Error: install.tar wasn’t found on the installation media. This happens because during part of the installation process. the USB drive is un-mounted and needs to be mounted again. It also expects to find install.tar at /install/install/install.tar and so we must mount the device to the /install path.   You don’t need to be a wizard to…

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Terminology: Understanding MDFs and IDFs

Many times, early on in my tinkering or trying to learn about computer systems, I would wonder about certain terms or ideas that would come up on a “higher level”. The capabilities of my brain sometimes couldn’t wrap up the thoughts that make up an idea or a concept into a single term, and so I didn’t understand some of these things, like when I saw MDF or IDF for the first time. MDF is short for main distribution frame. This is the central point of a network, no matter the size.…

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Cloud Hosting: Digital Ocean vs Vultr vs Linode

It’s probably not a hot debate, but among popular cloud hosting providers Digital Ocean, Vultr, and Linode, what you get for your dollar really varies. I’ve taken three popular cloud hosting providers (based upon my opinions and experience) and compared them to determine which service I might utilize for standard cloud VM deployment. Not only do the immediate offerings matter (such as resources and prices) but datacenter location and flexibility of working within a provider’s environment is also extremely important. Part One: Plans/Packages Digital Ocean: With Digital Ocean, $5/month will get you 1…

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Sophos UTM Country Blocking: Oops!

Background: My girlfriend has an AirBnB service for a spare room in her home. I have a Sophos UTM appliance running her home network. Okay! Last night my girlfriend received a text on behalf of our guest stating that the WiFi wasn’t working. We were out for pizza + beer, so we didn’t exactly rush home to check it out. […] This morning we got word again; “the WiFi isn’t working, they say they need to use the WeChat app” I logged in to the Wireless AP and it checked out. It’s…

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How To: Control Lenovo SA120 fan speeds from within FreeNAS

AndrewX192 has created a Python script to allow adjusting the fan speed of a Lenovo SA120. Step 1: Download the python script to your FreeNAS Log in to FreeNAS and open a shell Hit “paste” and copy below: curl https://raw.githubusercontent.com/AndrewX192/lenovo-sa120-fanspeed-utility/master/fancontrol.py > ./fancontrol.py To verify that this downloaded, run the command and look for the file. ls -alF Good! It is there. Step 2: Testing! On the next line, go ahead and execute the following command: python fancontrol.py 1 This will bring any attached Lenovo SA120 DAS down to the lowest…

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How To: Set up Client VPN Remote Access on Sophos UTM for iOS, iPhone, iPad

The iPhone supports IKEv2, IPsec, and L2TP Client VPN. Sophos UTM supports SSL, PPTP, L2TP over IPsec, IPsec, and more VPN protocols. For this guide, we are going to use iPhone’s L2TP VPN Client to remotely connect to our Sophos UTM. To start, log in to your Sophos UTM and select the “Remote Access” section Click L2TP over IPsec for compatibility with iOS   Enable the protocol by toggling the switch to “enabled” Choose Authentication Mode: Preshared key Create a secure key and repeat it 2x below Assign IP address…

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