2025-09-21
This article is compiled as a “cheat sheet” for SOHO/SMB networks: common issues, their symptoms, causes, quick fixes, and diagnostic checklists. Suitable for both engineers and admins who maintain the MikroTik ↔ Keenetic bundle.
📑 Navigation
1) EoIP “freezes” when transferring large files
Symptoms: SMB/FTP hangs, speed fluctuates, RDP drops.
Causes: incorrect MTU/MSS, fast-path with IPsec, NAT/Firewall errors.
2025-09-19
Introduction
WP-CLI is the official command-line tool for WordPress, allowing you to manage your sites without logging into the admin panel. With WP-CLI, you can install plugins, update WordPress core, manage users, handle database tasks, and even run advanced automation workflows.
In this guide, we’ll explore what WP-CLI is, how to install it, and provide practical examples of its most useful commands.
What is WP-CLI?
WP-CLI (WordPress Command Line Interface) is a PHP-based tool that enables direct interaction with WordPress through the terminal. It covers almost all admin tasks and sometimes goes beyond the WordPress dashboard:
2025-09-18
Introduction
Netplan is a utility for declarative network configuration in Linux (Ubuntu, Debian, and derivatives).
It is usually used for simple cases like Ethernet or Wi-Fi, but it can do much more:
- tunnel interfaces (IPIP, GRE, VXLAN, WireGuard),
- VLAN,
- bridges,
- bonding (interface aggregation).
These features allow building complex network topologies — from home VPNs to data centers and cloud environments.
Tunnel interfaces
Tunnels encapsulate packets of one protocol into another. They are used for VPNs, inter-server connections, or network isolation.
2025-09-17
Introduction
Imagine: ping works, DNS responds, ports are open, mtr shows no loss, but curl returns errors like connection reset by peer or SSL handshake failed. There’s clearly a problem, but standard tools are powerless.
At such moments, the only option is to look at the actual traffic — in other words, “listen to the wires.” This process is called packet sniffing or packet analysis. In this article, we’ll go through how to use three key tools: tcpdump, sngrep, and Wireshark.
2025-09-16
Introduction
Up to this point, we’ve used simple utilities for specific tasks:
ping checked connectivity,traceroute showed the path,ipconfig and arp helped with the local network,telnet and nc tested ports.
That’s like having a separate hammer, screwdriver, and wrench. But sometimes you need a multi-purpose tool. Today we’ll look at three such “all-in-one” tools:
mtr — ping + traceroute on steroids,nmap — universal network scanner,curl — a command-line browser.
mtr — Real-Time Traceroute 🚀
What does it do?
Combines the features of ping and traceroute. In real time, it shows latency and packet loss percentage for each hop along the path.
2025-09-15
Introduction
A server’s IP address is like the postal address of an apartment building. But to reach the right apartment, you need the door number. In networking, these doors are ports.
- HTTP runs on port 80.
- HTTPS — on port 443.
- Mail, databases, and other services listen on their own ports.
If a port is closed or nothing is listening on it, the site won’t open — even if the server is “alive.”
2025-09-14
Introduction
You’ve gone through all the checks from the previous articles:
- The computer has the correct IP address (
ipconfig). - The router responds (
ping 192.168.1.1). - Ping to a public address (
ping 8.8.8.8) works.
Looks like the internet is fine! But the browser won’t open google.com. 🤔
Welcome to the most common cause of such issues — DNS failures.
What is DNS? 📖
The internet runs on IP addresses (e.g., 142.250.184.110), but people prefer names (google.com).
2025-09-13
Introduction
In the previous article, we learned how to reach out to remote servers using ping and trace the path of packets with traceroute. But what if ping google.com doesn’t work, and traceroute stops right at the first step?
That’s a clear sign that the problem is nearby: on your computer, in the network cable, or in your home router. Before calling tech support, let’s check our own local network.
2025-09-11
In this guide, we’ll go through setting up an OpenVPN server on Ubuntu and connecting a Keenetic router to it. This setup is useful if you need to provide access to your home network or forward services (e.g., PBX or web server) through VPN.
1. Preparing the Ubuntu server
1.1 Installing packages
sudo apt update
sudo apt install -y openvpn easy-rsa iptables-persistent
1.2 Creating PKI (Easy-RSA v3)
make-cadir ~/easy-rsa
cd ~/easy-rsa
./easyrsa init-pki
./easyrsa build-ca nopass
Server keys
./easyrsa gen-req server nopass
./easyrsa sign-req server server
./easyrsa gen-dh
Client keys (for Keenetic)
./easyrsa gen-req keenetic nopass
./easyrsa sign-req client keenetic
TLS key (specifically tls-auth, not tls-crypt)
openvpn --genkey secret ta.key
1.3 Distribute keys
2025-09-10
In the previous article, we deployed a basic Jitsi Meet server using Docker.
Now let’s look at how to secure your server, enable authentication, and optimize performance for stable video calls.
Authentication: Invite-Only Access
By default, Jitsi Meet allows anyone to create rooms. To restrict access — enable Secure Domain.
- Open the
.env file and find the Prosody (XMPP server) section.ENABLE_AUTH=1
AUTH_TYPE=internal
Here, internal means that users will be stored locally.
