Your DHCP server must be in only one VLAN

Recently, we have made a major upgrade of the network infrastructure for one customer. We replaced the old switches and introduced the complete VLAN infrastructure. At the end of the day, everything seemed to be good.

Then, after two days, DUDE started to raise alarms related to DHCP service. We received a bunch of e-mails related to an empty DHCP pool. It was a mystery how this DHCP pool emptied when there are only 10 workstations and this happened during a public holiday when the offices were empty. Continue reading

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Renaming remote Windows computer using the command line

Whether you need to rename a local or remote Windows computer, you can perform that task in multiple ways. We all know how to do that using the GUI. Here is the mighty Jedi trick to do the same task from the command line. And from your workstation, too. Continue reading

Advanced disk repairing option in Windows 8 and later

A few months ago, I encountered a problem with one USB hard disk. Whenever it was attached to any PC, Windows will prompt that volume has errors. As always, we click on Scan and Fix option expecting that that would do the job.

This disk was one of a kind and now you can read about it. I tried a few times to repair it. Every time, the disk check passed and all was fine, until I again needed to reconnect the disk. Then the story repeated. Continue reading

Reading file details on the Windows Core system

If you want to view a file details in Windows with GUI, you need to right-click on the file in Explorer, select Properties from the context menu and then click on the Details tab. Easy.

Can you do the same task using only the command line? With a little magic and a few mighty tricks you can do that, too.

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Windows Update failed with the error code 8024402C

I have a very strict policy that servers must not access the Net. If a server needs to be accessible from the Net, it will be placed in the DMZ zone with very rigid firewall rules. To update all servers, I need to implement the WSUS server in the local network.

I never let servers update automatically. Rather, I let them notify me about available updates and then I will manually run an installation process.

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Reading system parameters using WMIC

A few months ago, I had a need to find the serial numbers on a few servers. This number is printed in small size letters either on a tag or sticker placed on the computer case. In most cases, that sticker isn’t visible without extracting the server from the rack. Too much hassle!

Luckily, virtually every brand name machine has its serial number inside the system’s BIOS. We just need access to that information. So, the information is there, but we can’t read it easily. The answer is to use WMI.

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