NETLOGON event 5807

Recently, I found a lot of NETLOGON warnings in the system log. As I know my network is very clean, I was very curious about this. Every anomaly in my network requires careful examination.

After analysis of the log file, I found the root cause of this warning. Over time, we added some servers in the test network and at the same time added them to the AD domain. However, I omitted to define this subnet range in the AD site structure.

 

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Updating iOS 10 beta to public version

My iPhone worked fine on the iOS 10 beta 2. Apple advises it won’t work any of the beta versions of any software, except during the test periods. The phone worked fine from my perspective and being lazy; I didn’t want to perform the update.

A couple of weeks ago though, the phone occasionally prompted with the message “A new iOS update is now available. Please update from the iOS 10 beta.”. Finally, over the last few days this prompt appeared every time the device was unlocked. Eventually, I decided to upgrade the iOS to the public version.

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Troubleshooting poor performances of virtual machines in an Oracle VirtualBox

Sometimes I have to give a presentation on IT. I like to make a such presentation to be dynamic, combining together slides and a live demonstration. I often use several VMs in the same time to simulate scenario.

Preparing one such presentation, I made a few mistakes in the configuration of the VMs. Eventually, one VM was too slow during startup. An audience on the presentation didn’t noticed the problem, as I covered it up with an another part of the demonstration.

After the presentation, I analyzed the whole situation and found the weak point – the wrong choice between VM’s parameters.

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Optimizing performance of the virtual machines in an Oracle VirtualBox

The Mikrotik User Meeting or MUM Serbia 2016 was only a few days ago, during which I delivered a presentation related to the Mikrotik IPSec services. Rather than repeat the presentation, I decided to combine the slides and live demonstration.

I will write about Mikrotik IPSec services in some another post. I mention this presentation because the demo part is important for today’s though. One of the virtual machines booted very slowly and this had some impact on the presentation.

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Repairing the server-side SSTP VPN on the Mikrotik router

A few months ago, we found a problem with one the Mikrotik Routerboard RB1100AH unit. We discovered that the fans are not working. As we have a cold spare unit, I just transferred the latest backup to the new unit.

After the reboot, everything began to work. That was easy on the first sight. However, I discovered soon that the remote offices are not connected to the central location. The VPN links were down.

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Watch the network with Mikrotik Netwatch

Whenever you have a network with more than a few devices or more than a couple users, you will need to know more about the network health. Whether you are just an advanced user, system administrator or technical support engineer, knowing the status of all devices inside the network is necessary.

We can use a full-scale network monitoring solution (NMS), like the Mikrotik Dude. However, we can fulfill our goal in a simpler yet effective manner. Mikrotik RouterOS includes some cool features. We can utilize the Netwatch service to check availability of the hosts inside the network.

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An offline installation of IE11

Before IE 11, the update process was very simple. You simply download a new installation file and run the installation process. Then you just needed to restart the computer and that’s it.

However, the Internet Explorer 11 (or IE11 in short) requires some other updates as its own prerequisites. If you just try to download and run a basic installation file, it will ask you to download other necessary updates. Many Windows 7 SP1 users knows this already.

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