Author Archives: Eelco Ligtvoet

About Eelco Ligtvoet

Dutch nerd

Hardening your PI: SSHD protection

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Steps to take to protect an internet-facing Raspberry PI (or other Debian) from brute-force SSH logins from subnets Note: Fail2ban 0.10.2 on 2020/12/22 Install firewall ufw and log analyzer fail2ban: sudo apt update sudo apt install ufw fail2ban (PiOS Buster: the sshd jail is enabled by default via /etc/fail2ban/jail.d/defaults-debian.conf) Copy… Read more »

Powershell: Get an indented process tree

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Process Tree

In PowerShell, there is the Get-Process cmdlet. However, this does not return the ParentProcessId property, so it is unsuitable for displaying an indented process tree, which you, for instance, could send by email. Luckily, there is the Get-WMIObject cmdlet that can return the ParentProcessId. How to get a Process Tree… Read more »

Reading the Windows Registry from PowerShell

Reading the Windows registry from PowerShell can be a bit cumbersome, when all you wanted to retrieve is the value of an item under a key, at least with PowerShell version before v5. The Get-ItemProperty can be used to enumerate the items and their values under a registry key, but… Read more »

Useful PowerShell functions and snippets

This post contains a few (short) useful PowerShell functions and snippets, that you can include in projects and/or your profile, and some which showcase some peculiar solutions to problems in PowerShell. This one is for use in your profile, so you can see in Alt-Tab which Powershell console is running… Read more »

Ubuntu 14.04 and up: Rename a volume group containing root

When checking my cloned Ubuntu 14.04 LTS VM, I noticed that it still contained the volume group name from the original, which is of course not desired. It seemed fairly simple, but I kept receiving an error with update-grub, reporting the old Volume Group name: /usr/sbin/grub-probe: error: failed to get… Read more »

Setting up a static IP address or Wifi on Raspberry PI 2 B

Setting up a static IP address or Wifi on Raspberry PI 2 B

Eth0 static IP address configuration On the latest version of Raspbian (in my case, Raspbian GNU/Linux 8), you should not use /etc/network/interfaces to set up your networks. All configuration has been offloaded to the dhcpcd client. For a static IP address on the eth0 interface, you’ll need to edit file /etc/dhcpcd.conf For… Read more »

HP Universal Printer PCL 6 driver cannot read printer capabilities

printer pcl 6 driver

This bug I encountered last week. While writing a system to define printers and TCP/IP ports in bulk on Windows 2008 R2 servers, I got the report from the testers that a color printer defined with the HP Universal Printer PCL 6 driver wasn’t recognized as color when the port… Read more »