David Stein

Connecting Offices: A Step-by-Step Guide to MikroTik Site-to-Site WireGuard

07/01/2026 / IT, Networking

WireGuard has revolutionized the way we think about VPNs. It’s faster than OpenVPN, leaner than IPsec, and significantly easier to configure. If you are running MikroTik hardware (RouterOS v7+), setting up a secure tunnel between two locations is now a 10-minute task. In this guide, we’ll walk through connecting Site A (Headquarters) to Site B […]

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PPPoE: The ISP’s Choice for Client Connections (and How to Set it Up)

02/01/2026 / Uncategorized

For Internet Service Providers (ISPs), managing thousands or even millions of client connections requires a robust and scalable solution. While simpler methods exist, many ISPs still rely on PPPoE (Point-to-Point Protocol over Ethernet) for its excellent control, billing integration, and session management capabilities. From an ISP’s perspective, PPPoE offers: This post will guide you through

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NK2 – migration of contact suggestion in Outlook

10/11/2025 / IT, Windows

Before uninstall open the current nk2 file with https://www.nirsoft.net/utils/outlook_nk2_edit.html, Create the backup (save as) of nk2 file. When you upgrade to Outlook 2010, Outlook 2013, or Outlook 2016, the nk2 file is automatically imported the first time you start Outlook, but sometimes it do not work. When you create a new Outlook mail profile or

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ISP Config – mTLS – website certificate protection

15/09/2025 / Internet, IT, Linux, Tutorials

This solution uses Let’s Encrypt as the certificate provider for the website and custom certificates for mTLS authentication. Connect to the ISP Config server and prepare certificates Generate CA certificate Generate client certificate Export client certificate After export, you need to import the certificate into your OS system. Copy CA certificate to the website folder

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Mikrotik – quick OpenVPN setup

03/09/2025 / IT, Networking

In this post, you will find the basic commands to set up OpenVPN on a Mikrotik router. OVPN – setup OVPN – config example RSA – certificate decrypt for Windows Find the openssl.exe, standard location is C:\Program Files\openvpn\bin

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Kerio API – PHP get users mailboxes,sizes and quotas

08/08/2025 / IT

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Project – FiresSMS – Dockerized sending SMS by GSM modem

26/07/2025 / FireSMS, IT, My projects

FiresSMS https://github.com/Fires04/FiresSMS

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Zabbix – usefull tips and commands

20/07/2025 / IT, Zabbix

Testing triggers If you need to test the Zabbix notification or response for specific alert severity, here is a little walkthrough on how you can do it easy way. First, create the new host in Zabbix web interface. Fill only the hostname. Then, create a new item under the newly created host. Fill the name,

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TL;DR – Zabbix docker compose upgrade

20/07/2025 / IT, Linux, Zabbix

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Migrate Microsoft domain controller (DC)

16/06/2025 / IT, Tutorials, Windows

Upgrading your Active Directory infrastructure isn’t a trivial task—but by following Microsoft’s recommended approach, you can migrate Domain Controllers (DCs) smoothly and securely. Here’s a clean, step-by-step guide to help you transition from Windows Server 2012 R2 DCs to fresh 2019 servers with minimal downtime. 1. Verify and Clean Up Current Environment 2. Stand Up a New

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