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Best Home Wi-Fi settings for Maximum Speed and Internet coverage in Europe

Tuesday, July 21st, 2026

best-home-wifi-settings-for-maximum-speed-and-internet-coverage-europe-simple-steps-to-improve-your-home-wifi-signal

A fast broadband subscription is only part of the equation to have excellent internet air connectivity configuration for a home / work Wi-Fi Internet Router.
Even if you pay for good stable gigabit fiber options connection, poor Wi-Fi configuration can reduce your real-world speeds by more than half which might make working with devices have annoying temporary slownesses or even disruptions, when exchanging data to internet.

Our modern homes are filled with smart TVs, streaming devices, gaming consoles, laptops, smartphones, and IoT devices – all competing to take over fastest and stablest connectivity to the wireless device bandwidth.
Thus optimizing Wi-Fi router connectivity settings is no longer optional but is kind oa  in year 2026.

This snall guide would covers most of the best practices for configuring a home Wi-Fi network for maximum speed, stability, and security across Europe.

1. Choose the Right Wi-Fi Standard

Your router determines the maximum performance of your wireless network.


Recommended standards:

  • Wi-Fi 6 (802.11ax): Best value for most homes
  • Wi-Fi 6E: Excellent if your devices support the new 6 GHz band
  • Wi-Fi 7: Future-proof and ideal for multi-gigabit internet connections

! Avoid, using older Wi-Fi 5 or Wi-Fi 4 equipment unless upgrading is not possible !

2. Use the Best Frequency Band

Modern routers typically broadcast multiple wireless bands.


2.4 GHz Advantages:

  • Longer range
  • Better wall penetration
  • Disadvantages:
  • Lower speeds
  • More interference
  • Congested in apartments


2.4GHz Ideal for:

  • Smart home devices
  • Printers
  • Cameras

5 GHz Advantages:

 

  • Higher throughput
  • Lower latency
  • Less interference
  • Ideal for:
  • Streaming
  • Gaming
  • Video conferencing
  • Workstations


6 GHz (Wi-Fi 6E / Wi-Fi 7) Advantages:

 

  • Extremely low interference
  • Highest available speeds
  • Very low latency


6Ghz Wifi is usual use is:

With most modern Devices, such as (IoT connected devices, Wifi Gaming PCs, High-performance laptops, For large files transfer), tech quipment that looking for best Internet connectivity via air.. 

3. Position Your Router Correctly

best-wifi-router-placement-location-position-your-wireless-router-correctly-for-optimial-internet-air-speed

Router placement has a greater impact than many people realize.

Best practices for Router Positioning:

  • Place the router near the center of your home.
  • Position it on a shelf or table rather than on the floor.
  • Avoid placing it inside cabinets.
  • Keep it away from large metal objects.
  • Maintain distance from microwaves and cordless phones.
  • Keep antennas vertical unless the manufacturer recommends otherwise.
  • In multi-story homes, position the router between floors whenever possible.

4. Select the Best Wireless Channel

Channel congestion is one of the biggest causes of slow Wi-Fi.

For Europe (European Union countries):

For 2.4 GHz Wifi;

Use signal spread only:

  • Channel 1
  • Channel 6
  • Channel 11


These channels minimize overlap.

For 5 GHz;

 

Enable automatic channel selection or manually choose a channel with low congestion using a Wi-Fi analyzer.

5. Use the Correct Channel Width

For 2.4 GHz WiFi


Use:
+ 20 MHz
Avoid:
– 40 MHz unless there are very few neighboring networks.

For 5 GHz

Recommended:
+ 80 MHz
+ Use 160 MHz only if:
+ Few neighboring networks exist
+ Your devices support it

For 6 GHz

Use:
160 MHz or wider when available.

6. Enable WPA3 Security


Best WPA3 selection:

WPA3-Personal


For older devices require Backwards compatibility (keep enabled):
WPA2/WPA3 Mixed Mode

Avoid:
– WEP
– WPA
– Open networks
– Strong security helps prevent unauthorized users from consuming bandwidth.


7. Separate IoT Devices in different network

Many smart home devices generate unnecessary wireless traffic.
Create seperate networks for:

  • Main networ
  • Guest network
  • IoT network

This improves performance and enhances security.

8. Enable OFDMA and MU-MIMO

Modern Wi-Fi 6 routers support technologies that improve efficiency.
OFDMA

Allows multiple devices to share wireless resources efficiently.
MU-MIMO
Enables simultaneous communication with multiple devices.

Both should remain enabled.

9. Update Router Firmware

Manufacturers regularly release updates that improve the Performance, Security, Stability, Compatibility.
As script kiddie "hackers" threaths raise seriously day by day, when possible always, do:

  • Enable automatic firmware updates whenever possible.

10. Use Quality of Service (QoS)


Use the router to QoS prioritizes important traffic
Usual candidates for higher priorty internet traffics configs are:

  • Streaming, Work VPN traffic
  • Gaming, Video calls


Se as Lower priority ones :

  • Downloads
  • Cloud automated backups, etc.

11. Disable Legacy Wi-Fi Modes


Older compatibility modes, has advantages for interoperability but does reduce network efficiency, so most people would like to disable it.

Disable wifi mode transmission:

– 802.11b
– 802.11g


For Performance use instead the newer transmissions:

+ 802.11n
+ 802.11ac
+ 802.11ax

12. Always Prefer Wired Connections for High-Bandwidth Devices

alwayes-prefer-wired-connections-for-high-bandwidth-devices-cable-network-connection-should-be-always-first-choice

Connect these devices via Ethernet whenever possible:

  • NAS systems (Storages), Desktop PCs (most important candidates for UTP connectivity)
  • Gaming consoles, Smart TVs, Streaming boxes (secondary but also important to not disrupt your fun time)


Note !:
 Every cable connected device would have possible impact on any other connected Wi-Fi devices such as Mobile phones.
Every wired device reduces wireless congestion!

13. Use Mesh Wi-Fi for large sized sq. meter homes

If your home exceeds approximately 150–200 m² or has multiple floors, consider a mesh Wi-Fi system instead of relying on a single router.


Benefits includes:

  • Better coverage
  • Seamless roaming
  • Higher overall speeds
  • Reduced dead zones

14. Monitor Network Usage


Many routers provide tools to identify bottlenecks. Some common ones are

  • Bandwidth-heavy devices, Weak connections

     

     

     

     

    Review these statistics as regular as possible to optimize your network and have decent internet connectivty.

  • Congested channels, Signal quality issues

15. Understand European Wi-Fi Regulations

European countries follow ETSI regulations for wireless spectrum.
Most routers sold in Europe automatically comply with regional requirements, including:

Permitted transmit power, DFS (Dynamic Frequency Selection), follow approved set wireless channels.

! Avoid changing the router's region setting, as this may violate local regulations and reduce compatibility. !

Example Configuration for a Modern European Home (Recommended Value Settings)
 

  1. Wi-Fi Standard    Wi-Fi 6 or newer
  2. Security    WPA3-Personal
  3. 2.4 GHz Channel    1, 6, or 11
  4. 2.4 GHz Width    20 MHz
  5. 5 GHz Width    80 MHz
  6. 6 GHz Width    160 MHz (if supported)
  7. Firmware    Automatic updates enabled
  8. QoS    Enabled
  9. OFDMA    Enabled
  10. MU-MIMO    Enabled
  11. Smart Connect    Enabled unless manual band control is preferred
  12. DNS    ISP, Cloudflare (1.1.1.1), or Google Public DNS (8.8.8.8)


Common mistakes to avoid

 

  • Placing the router inside a cabinet.
  • Using outdated firmware.
  • Running all devices on the 2.4 GHz band.
  • Selecting crowded wireless channels.
  • Leaving the default administrator password unchanged.
  • Using Wi-Fi extenders instead of a proper mesh system in large homes.
  • Connecting high-bandwidth devices wirelessly when Ethernet is available.

Conclusion

Optimizing a home Wi-Fi network involves more than purchasing a fast router. Proper placement, choosing the right frequency bands, selecting appropriate channels, keeping firmware updated, and enabling modern Wi-Fi features such as OFDMA and MU-MIMO can significantly improve speed, reliability, and coverage.
For most European households, a centrally located Wi-Fi 6 router configured with WPA3 security, 80 MHz channels on the 5 GHz band, and Ethernet connections for high-bandwidth devices provides an excellent balance of performance, security, and future readiness.

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Posted in Curious Facts, Educational, Everyday Life, Hacks, Performance Tuning, System Optimization | No Comments »

Why modern Linux systems feel Slow and how to Speed it up. Common RAM, CPU, and performance Linux problems in 2026 explained

Monday, May 18th, 2026

For years Linux we the Linux users proudly mocked Windows for bloated resource usage and that was a reason for many enthusiasts like me to start in the Linux realm.
There used to be the good old times where, lightweight distributions running comfortably inside 128MB of RAM were once common, and old computers and the hackers good old ThinkPads series were perfect for becoming a computer professional.

Fast-forward trip to 2026 and many modern GNU / Linux desktop's resource hunger has topped UP and a typical GUI environment such as Gnome is consuming as minimum 2 GB of RAM and often  4GB of RAM immediately after enters through the Login manager and machine. So many of the old computers if even running for 7-8 years and served well once updated or reused with Linux on a fresh install  prformance feels really bad. There of course work arounds to that as there are distributions such PuppyLinux / Tiny Core Linux / Linux Lite / Lubutuntu and even multiple articles online suggesting on how to place an ordinary Debian on Ubuntu and optimize it to work better on older hardware but still this article might be of help not only for old school Linux fans who install on old harware but also for sysadmins who has to deploy and install brand new Linux distributions and want to squeeze best of performance from the machine and make it as minimimalistic as possible in order to reduce the number of problems that might occur for system management.

So What happened, to make Linux performance degrade so dramatically over last 15 years ?

Old Hardware feels Slower Even With Linux

People often install Linux expecting miracles on ancient hardware.

Modern workloads assume:

  • SSD storage
  • multiple CPU cores
  • AVX instructions
  • GPU acceleration
  • large memory pools

Even lightweight Linux distributions struggle when rendering modern web applications on decade-old CPUs.

A 2007 machine browsing modern JavaScript-heavy websites experiences a fundamentally different workload than it did originally.

Web site use became computationally expensive.

 

Modern Linux Is Carrying the Weight of the development of Tech and Internet industry

A contemporary Linux desktop is no longer just:

  • X11
  • a window manager
  • a browser
  • a terminal emulator

Modern systems now run dozens of background services (as people run into complexity more and more instead of minimalism). Even a basic Linux install often runs by default things such as:
telemetry collectors, hardware abstraction layers, sandboxing frameworks, package management daemons, web server management platforms, indexing systems, GPU compositors, browser engines that resemble miniature operating systems and even with some specific distros embedded containers.

A typical desktop session environment on Linux today often includes as a base a bunch of software that is not always necessery such as:

  • systemd
  • dbus-daemon
  • pipewire
  • wireplumber
  • NetworkManager
  • xdg-desktop-portal
  • gvfsd
  • tracker-miner
  • udisksd
  • polkitd
  • bluetoothd
  • ModemManager
  • cupsd
  • flatpak-session-helper

Many younger users won't  never notice the burden of having those services running all time on the hardware as hardware today is mostly powerful and modern PC and notebooks often ship with 16GB or even some gaiming machines have 32 GB of memory.

As the default amount of memory on a laptop PC has become so abundant as 16GB RAM has become  "normal / standard ",  so software developers stopped aggressively optimizing memory consumption, plus the inclusing of AI vibe coding today and the abundant resource makes things with program optimization even more bloated.

The result of all this is more and more software entropy (the tendency of software systems to become more disorganized, complex, and harder to maintain over time).

The older UNIX philosophy no longer remembered by newer developers is completely forgotten. The old unix thinking was "Do one thing well.",
the new is "use everything no matter the efficiency if that would save you time"

As a result modern desktop applications instead ship entire browser engines for  simple things as displaying buttons.
This is exactly where Linux desktop gets heavily loaded and cause for whole system to work sluggish even on newer hardware. 
Very large part of those ineffiicient developed is caused by Electron:

Electron Framework for building Desktop apps worsened Linux performance

One of the largest reasons modern Desktop Linux / Windows systems is Electron (a framework for building desktop applications using JavaScript, HTML, and CSS).

Electron bundles essentially with:

  • Chromium
  • Node.js
  • V8 JavaScript engine
  • application runtime
  • UI rendering engine

and this is used in …inside many of the third party applications, which unfurtunately has to be used also on Linux, few examples that has heavy electron use are:

  • Discord client
  • Slack client
  • VS Code
  • Element 
  • Spotify
  • Visual Studio Code
  • Discord
  • Signal Desktop
  • Postman
  • Countless App launchers part of extra packages that one needs to use on Linux Desktop

…are frequently separate Chromium instances or use large part of chromium libs pretending to be native applications.

1. Finding top resource hungry Apps on Linux

To get a list of most memory heavy Apps on a Linux system:

# ps aux –sort=-%mem | head

 

You may discover that “lightweight desktop apps” and background services are consuming much more RAM than imagined.

Measuring Real Resource Usage Properly

Many users misunderstand Linux memory reporting.

Linux aggressively uses RAM for:

  • filesystem cache
  • buffers
  • inode caching

Note! Unused RAM is wasted RAM.

# free -h

Focus on:

  • available memory
  • swap activity
  • sustained pressure

Better command tools to optimize OS include:

htop
btop
smem
iotop
vmstat

Systemd  Useful but running default unused services

Mentioning systemd still starts wars on Linux forums.

Reality is nuanced.

Systemd solved real problems:

  • dependency management
  • predictable service startup
  • cgroup integration
  • journal logging
  • parallel boot
  • service supervision

However, it also dramatically expanded the scope of PID 1 responsibilities.

Leading to many Linux-es to now launch numerous services laying around, not known by the users and never (intially needed).

If you want to check and optimize systemd ecosystem to improve performance

2. Check systemd OS boot chain and disable unnecessery services

# systemd-analyze blame

And inspect active systemd units:

# systemctl list-units –type=service

Many Linux distributions has by default setup of unused:

  • printer services on systems without printers
  • modem services on desktops without modems
  • Bluetooth stacks on machines without Bluetooth devices
  • indexing daemons nobody uses

Disable unnecessary services carefully:

sudo systemctl disable –now ModemManager
sudo systemctl disable –now bluetooth
sudo systemctl disable –now cups


This alone will reduce memory usage and boot time.
A common set of unused Apps on Desktop and servers goes like this:
 

# Printing system (disable if you never use printers)

# systemctl disable –now cups.service cups-browsed.service

# Bluetooth support (disable if you don’t use Bluetooth devices)

# systemctl disable –now bluetooth.service

# Mobile broadband / modem support (disable if no 4G / 5G dongles)

# systemctl disable –now ModemManager.service

# Network discovery (AirPrint, LAN service discovery; disable if not needed)

# systemctl disable –now avahi-daemon.service

# Location services for apps/browser geolocation (disable if not used)

# systemctl disable –now geoclue.service

# Ubuntu crash reporting services (safe to disable for privacy/no reporting)

# systemctl disable –now apport.service whoopsie.service

# Desktop search indexing (GNOME file search; disable if you don’t use fast search)

# systemctl disable –now tracker-miner-fs.service tracker-extract.service tracker-store.service

 

For deeper analysis check out systemd cg groups use:

# systemd-cgtop

Or inspect slab allocator usage:

slabtop


3. Avoid using Flatpak and Snap for extra Apps

Flatpak and Snap Increase Isolation, provides many modern Apps that are not default shipped by Debian / Ubuntu / Fedora OS  etc (Deb / RPM) repos and keeps packages easily at latest but also puts great worthless overhead on system.
 

a) Modern packaging systems like Flatpak and Snap (Pros) prioritize:

  • sandboxing
  • dependency isolation
  • reproducibility
  • cross-distribution compatibility

This is good for security, however it comes at a cost.

b) Use of Flatpak and Snap pack. managers downsides

Flatpak applications frequently duplicate:

  • runtimes
  • libraries
  • graphics stacks
  • helper services

Snap packages compress applications into loop-mounted filesystem images which increase startup overhead and general memory fragmentation.

Inspect mounted Snap filesystems

# mount | grep snap


Inspect Flatpak runtimes:

# flatpak list


Considering that, traditional native packages remain significantly leaner in many cases.

4. Use Minimalistic GUI Desktop environment to reduce resource and use of complexity on Linux

Being mimimalist nowadays in a world of abundancy is considered wrong. However minimalism has its well known provent benefits. 

Wayland Is Efficient,  but X11 env with Minimalist GUI is better

Wayland itself is not inherently bloated.

However, modern compositors increasingly rely on:

  • GPU acceleration
  • animation pipelines
  • texture buffering
  • fractional scaling
  • HDR rendering
  • Vulkan / OpenGL abstractions

This improves:

  • smoothness
  • latency
  • security
  • multi-monitor support

…but increases baseline GPU and memory usage and still for performance cautious desktop users it is most likely not the best option.

For example, try to compare CPU / Mem / Disk use of:

  • Openbox on X11
  • KDE Plasma on Wayland with effects enabled

The performance difference is dramatic.


If you want to be a Linux Minimalist (benefit) and get astonishingly low resource usage try:

  • dwm
  • i3
  • bspwm
  • Openbox
  • Wmaker
  • XFCE
  • IceWM

Switching to one of those Linux ecosystem instead of the default heavy GNOME or KDE permits even further optimizations on Graphical environment level,  if users intentionally choose it. The downsides of that is twitching it will take you usually longer but if you setup one and the same desktop with the basic minimalist environment and you keep using it for daily work / development for years, invested time is worth.

5. Use browser extensions, habits or a lightweight  browser. 

Web browser a common source of slowness 

Web Browsers, became nowadays a fully featured Operating Systems. On many machines they are the largest consumers of RAM on Linux systems and on old computers main source of slowness. On older PCs try to use other small browser alternatives

A single browser tab may include:

  • isolated sandbox process
  • JavaScript runtime
  • GPU process
  • extension subsystem
  • video decoder
  • site isolation sandbox
  • service workers

a) Inspect Chromium process trees

# ps -ef | grep chromium

b) Inspect Firefox process trees

about:processes

 

A few “simple” tabs can easily consume several gigabytes.

The modern web itself is bloated:

  • gigantic JavaScript frameworks
  • endless analytics
  • autoplay video
  • AI scripts
  • tracking engines
  • real-time rendering

Shamefully, many websites today consume more RAM than entire operating systems from the early 2000s.

If you have to work on a PC with 4 or 8 GB with Linux maybe you can try to use a GUI browser only when necessery and for general reading and stuff use a minimalist version of browsers such as using a text / console web  browser and ones that are capable to support ncurses and javascript partially, a good candidate for a real console maniac or an old school hacker will be some of below:

  • Lynx (lightest, pure text)
  • w3m (text browser but supports javascripts partially)
  • Links / Links2 (fast, ultra-lightweight web browser works in both text and gui modes)
    NetSurf (graphical web browser built from scratch with its own independent layout and rendering engine, performs poor with javascript)
  • Browsh (can be often used instead of fully functional browser but buggy)

xlinks2-graphical-mode-lightweight-browser-linux

c) Use Lightweight Browsing Habits

Extensions matter enormously.

Block:

  • ads
  • trackers
  • autoplay
  • unnecessary scripts

uBlock Origin (free and open source browser block extension) alone can dramatically reduce CPU and RAM consumption.

Final words; the modern computing efficiency degredal

What a paradox, Modern hardware is unbelievably powerful, yet modern software consumes resources at almost the same rate hardware improves.

This phenomenon is partially explained by:abstraction layers, developer convenience, use of cross-platform frameworks, increased security isolation, the web technologies heaviness and reduced optimization pressure.

Even though the degredal in perforamance on old hardware, Linux itself remains extremely efficient at the kernel level.

The bloat largely exists and widens though in:

  • userland
  • desktop ecosystems
  • browser-centric software culture
     

The computing as we know it changed.

What once was: terminal-centric, native, lightweight,locally optimized, inter-dependent

turned over  last 10 years: browser-centricm, all time cloud-connected, sandboxed, abstraction-heavy, outer dependent

The good news is that GNU / Linux still gives users freedom, even though the freedom has reduced.

Even though the performance reduced,  Linux still remains one of the few environments where users retain meaningful control over their data and system complexity in the AI, Clouds era

 

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Posted in Curious Facts, Educational, Hacks, Linux, Linux and FreeBSD Desktop, Performance Tuning, System Administration, System Optimization | No Comments »

How to Harden a Linux Server in 2025 – Practical Steps for Sysadmins to protect against hackers and bots

Thursday, December 11th, 2025

linux_server-hardening-practical-steps-for-sysadmins-protecting-machine-vs-hackers-and-bots-good-practices

Securing a Linux server has never been more importan than ever these days..
With automated attacks, AI-driven exploits, and increasingly complex infrastructure, even a small misconfiguration can lead to a serious breach.
But wait, you don't have to wait to get bumped by a random script kiddie. Good news is you can mitigate a bit attacks with just a few practical and pretty much standard steps, that can can drastically increase your server’s security.

Below is a straightforward, battle-tested hardening guide suitable for Debian, Ubuntu, CentOS, AlmaLinux, and most modern distributions.

1. Keep the System Updated (But Safely)

Outdated packages remain the #1 cause of server compromises.
On Debian/Ubuntu:

# apt update && apt upgrade -y

# apt install unattended-upgrades

On RHEL-based systems:
 

# dnf update -y

# dnf install dnf-automatic

Enable security-only auto-updates where possible. Full auto-updates may break production apps, so use them carefully.

2. Create a Non-Root User and Disable Direct Root Login
 

Attackers constantly brute-force “root”. Avoid letting them.
 

# adduser sysadmin

# usermod -aG sudo sysadmin

Then edit SSH:

# vim /etc/ssh/sshd_config

Set:

PermitRootLogin no

PasswordAuthentication no

And restart:

# systemctl restart sshd


Use SSH keys only.

3. Install a Firewall and Block Everything by Default

UFW (Debian/Ubuntu):

# ufw default deny incoming

# ufw default allow outgoing

#ufw allow ssh

# ufw enable

Firewalld (RHEL/AlmaLinux):

# systemctl enable firewalld –now

# firewall-cmd –permanent –add-service=ssh

# firewall-cmd –reload

Turn off any unneeded ports immediately.

4. Protect SSH with Fail2Ban

Fail2Ban watches log files for suspicious authentication attempts and blocks offenders.

# apt install fail2ban -y

or

# dnf install fail2ban -y

Enable:

# systemctl enable –now fail2ban

To harden SSH jail:

[sshd]

enabled = true

maxretry = 5

bantime = 1h

findtime = 10m

5. Enable Kernel Hardening

Install sysctl rules that protect against common attacks:

Create /etc/sysctl.d/99-hardening.conf:

kernel.kptr_restrict = 2

kernel.sysrq = 0

net.ipv4.conf.all.rp_filter = 1

net.ipv4.tcp_synack_retries = 2

net.ipv4.conf.all.accept_redirects = 0

net.ipv4.conf.all.send_redirects = 0

net.ipv4.conf.all.log_martians = 1

Apply:

# sysctl –system

6. Install and Configure AppArmor or SELinux

Mandatory Access Control significantly limits damage if a service gets compromised.

  • Ubuntu / Debian uses AppArmor by default — ensure it's enabled.
  • RHEL, AlmaLinux, Rocky use SELinux — keep it in enforcing mode unless absolutely necessary.

Check SELinux:

# getenforce

You want:

Enforcing but hopefully you will have to configure all your machine services to venerate and work correctly with selinux enabled.

7. Scan the System with Lynis

Lynis is the best open-source Linux security auditing tool.

# apt install lynis

# lynis audit system

It provides a security score and actionable suggestions.

8. Use 2FA for SSH (Optional but Highly Recommended)

Use Two Factor Authentication:

a. Freely with Oath toolkit – you can read how in my previous article how to set up 2fa free software authentication on Linux

or

b. Install Google Authenticator:

# apt install libpam-google-authenticator

# google-authenticator

Enable in /etc/pam.d/sshd:

auth required pam_google_authenticator.so

And in SSH config:

ChallengeResponseAuthentication yes

Restart SSH.

9. Separate Services Using Containers or Systemd Isolation

Even simple servers can benefit from isolation.

Systemd sandbox options:

ProtectSystem=full

ProtectHome=true

ProtectKernelTunables=true

PrivateTmp=true

Add these inside a service file under:

/etc/systemd/system/yourservice.service

It prevents processes from touching parts of the system they shouldn’t.

10. Regular Backups Are Part of Security

A secure server with no backups is a disaster waiting to happen.

Use:

  • rsync
  • borgbackup
  • restic
  • Cloud object storage with versioning

Always encrypt backups and test restore procedures.

Conclusion

Hardening a Linux server in 2025 requires vigilance, good practices, and layered security. No single tool will protect your system — but when you combine SSH security, firewalls, Fail2Ban, kernel hardening, and backups, you eliminate the majority of attack vectors.

 

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Posted in Computer Security, Linux, System Administration, System Optimization | No Comments »

How to Set Up SSH Two-Factor Authentication (2FA) on Linux Without Google Authenticator with OATH Toolkit

Wednesday, November 5th, 2025

install-2-factor-free-authentication-google-authentication-alternative-with-oath-toolkit-linux-logo

Most tutorials online on how to secure your SSH server with a 2 Factor Authentication 2FA will tell you to use Google Authenticator to secure SSH logins.

But what if you don’t want to depend on Google software – maybe for privacy, security, or ideological reasons ?

Luckily, you have a choice thanks to free oath toolkit.
The free and self-hosted alternative: OATH Toolkit has its own PAM module  libpam-oath to make the 2FA work  the openssh server.

OATH-Toolkit is a free software toolkit for (OTP) One-Time Password authentication using HOTP/TOTP algorithms. The software ships a small set of command line utilities covering most OTP operation related tasks.

In this guide, I’ll show you how to implement 2-Factor Authentication (TOTP) for SSH on any Linux system using OATH Toolkit, compatible with privacy-friendly authenticator apps like FreeOTP, Aegis, or and OTP.

It is worthy to check out OATH Toolkit author original post here, that will give you a bit of more insight on the tool.

1. Install the Required Packages

For Debian / Ubuntu systems: 

# apt update
# apt install libpam-oath oathtool qrencode
...

For RHEL / CentOS / AlmaLinux:
  

# dnf install pam_oath oathtool

The oathtool command lets you test or generate one-time passwords (OTPs) directly from the command line.

2. Create a User Secret File

libpam-oath uses a file to store each user’s secret key (shared between your server and your phone app).

By default, it reads from: 

/etc/users.oath

Let’s create it securely and set proper permissions to secure it:
  

# touch /etc/users.oath

# chmod 600 /etc/users.oath

Now, generate a new secret key for your user (replace hipo with your actual username):
  

# head -10 /dev/urandom | sha1sum | cut -c1-32

This generates a random 32-character key.
Example: 

9b0e4e9fdf33cce9c76431dc8e7369fe

Add this to /etc/users.oath in the following format: 

HOTP/T30 hipo - 9b0e4e9fdf33cce9c76431dc8e7369fe

HOTP/T30 means Time-based OTP with 30-second validity (standard TOTP).

Replace hipo with the Linux username you want to protect.

3. Add the Key to Your Authenticator App

Now we need to add that secret to your preferred authenticator app.

You can create a TOTP URI manually (to generate a QR code): 

$ echo "otpauth://totp/hipo@jericho?secret=\
$(echo 9b0e4e9fdf33cce9c76431dc8e7369fe \
| xxd -r -p | base32)"

You can paste this URI into a QR code generator (e.g., https://qr-code-generator.com) and scan it using FreeOTP , Aegis, or any open TOTP app.
The FreeOTP Free Ap is my preferred App to use, you can install it via Apple AppStore or Google Play Store.

Alternatively, enter the Base32-encoded secret manually into your app:

# echo 9b0e4e9fdf33cce9c76431dc8e7369fe | xxd -r -p | base32

You can also use qrencode nice nifty tool to generate out of your TOTP code in ASCII mode and scan it with your Phone FreeOTP / Aegis App and add make it ready for use:

# qrencode –type=ANSIUTF8 otpauth://totp/hipo@jericho?secret=$( oathtool –verbose –totp 9b0e4e9fdf33cce9c76431dc8e7369fe –digits=6 -w 1 | grep Base32 | cut -d ' ' -f 3 )\&digits=6\&issuer=pc-freak.net\&period=30

qrencode-generation-of-scannable-QR-code-for-freeotp-or-other-TOTP-auth

qrencode will generate the code. We set the type to ANSI-UTF8 terminal graphics so you can generate this in an ssh login. It can also generate other formats if you were to incorporate this into a web interface. See the man page for qrencode for more options.
The rest of the line is the being encoded into the QR code, and is a URL of the type otpauth, with time based one-time passwords (totp). The user is “hipo@jericho“, though PAM will ignore the @jericho if you are not joined to a domain (I have not tested this with domains yet).

The parameters follow the ‘?‘, and are separated by ‘&‘.

otpauth uses a base32 hash of the secret password you created earlier. oathtool will generate the appropriate hash inside the block:

 $( oathtool –verbose –totp 9b0e4e9fdf33cce9c76431dc8e7369fe | grep Base32 | cut -d ' ' -f 3 )

We put the secret from earlier, and search for “Base32”. This line will contain the Base32 hash that we need from the output:

Hex secret: 9b0e4e9fdf33cce9c76431dc8e7369fe
Base32 secret: E24ABZ2CTW3CH3YIN5HZ2RXP
Digits: 6
Window size: 0
Step size (seconds): 30
Start time: 1970-01-01 00:00:00 UTC (0)
Current time: 2022-03-03 00:09:08 UTC (1646266148)
Counter: 0x3455592 (54875538)

368784 
From there we cut out the third field, “E24ABZ2CTW3CH3YIN5HZ2RXP“, and place it in the line.

Next, we set the number of digits for the codes to be 6 digits (valid values are 6, 7, and 8). 6 is sufficient for most people, and easier to remember.

The issuer is optional, but useful to differentiate where the code came from.

We set the time period (in seconds) for how long a code is valid to 30 seconds.

Note that: Google authenticator ignores this and uses 30 seconds whether you like it or not.

4. Configure PAM to Use libpam-oath

Edit the PAM configuration for SSH: 

# vim /etc/pam.d/sshd

At the top of the file, add: 

auth required pam_oath.so usersfile=/etc/users.oath window=30 digits=6

This tells PAM to check OTP codes against /etc/users.oath.

5. Configure SSH Daemon to Ask for OTP

Edit the SSH daemon configuration file:
  

# vim /etc/ssh/sshd_config

Ensure these lines are set:
  

UsePAM yes
challengeresponseauthentication yes
ChallengeResponseAuthentication yes
AuthenticationMethods publickey keyboard-interactive
##KbdInteractiveAuthentication no
KbdInteractiveAuthentication yes

N.B.! The KbdInteractiveAuthentication yes variable is necessery on OpenSSH servers with version > of version 8.2_ .

In short This setup means:
1. The user must first authenticate with their SSH key (or local / LDAP password),
2. Then enter a valid one-time code generated from TOTP App from their phone.

You can also use Match directives to enforce 2FA under certain conditions, but not under others.
For example, if you didn’t want to be bothered with it while you are logging in on your LAN,
but do from any other network, you could add something like: 

Match Address 127.0.0.1,10.10.10.0/8,192.168.5.0/24
    Authenticationmethods publickey

6. Restart SSH and Test It

Apply your configuration:
  

# systemctl restart ssh

Now, open a new terminal window and try logging in (don’t close your existing one yet, in case you get locked out): 

$ ssh hipo@your-server-ip

You should see something like: 

Verification code:

Enter the 6-digit code displayed in your FreeOTP (or similar) app.
If it’s correct, you’re logged in! Hooray ! 🙂

7. Test Locally and Secure the Secrets

If you want to test OTPs manually with a base32 encrypted output of hex string: 

# oathtool --totp -b \
9b0e4e9fdf33cce9c76431dc8e7369fe

As above might be a bit confusing for starters, i recommend to use below few lines instead:

$ secret_hex="9b0e4e9fdf33cce9c76431dc8e7369fe"
$ secret_base32=$(echo $secret_hex | xxd -r -p | base32)
$ oathtool –totp -b "$secret_base32"
156874

You’ll get the same 6-digit code your authenticator shows – useful for debugging.

If you rerun the oathtool again you will get a difffefrent TOTP code, e.g. :

$ oathtool –totp -b "$secret_base32"
258158


Use this code as a 2FA TOTP auth code together with local user password (2FA + pass pair),  when prompted for a TOTP code, once you entered your user password first.

To not let anyone who has a local account on the system to be able to breach the 2FA additional password protection,
Ensure the secrets file is protected well, i.e.: 

# chown root:root /etc/users.oath
# chmod 600 /etc/users.oath

How to Enable 2FA Only for Certain Users

If you want to force OTP only for admins, create a group ssh2fa: 

# groupadd ssh2fa
# usermod -aG ssh2fa hipo

Then modify /etc/pam.d/sshd: 

auth [success=1 default=ignore] pam_succeed_if.so \
user notingroup ssh2fa
auth required pam_oath.so usersfile=/etc/users.oath \
window=30 digits=6

Only users in ssh2fa will be asked for a one-time code.

Troubleshooting

Problem: SSH rejects OTP
Check /var/log/auth.log or /var/log/secure for more details.
Make sure your phone’s time is in sync (TOTP depends on accurate time).

Problem: Locked out after restart
Always keep one root session open until you confirm login works.

Problem: Everything seems configured fine but still the TOTP is not accepted by remote OpenSSHD.
– Check out the time on the Phone / Device where the TOTP code is generated is properly synched to an Internet Time Server
– Check the computer system clock is properly synchornized to the Internet Time server (via ntpd / chronyd etc.), below is sample:

  • hipo@jeremiah:~$ timedatectl status
                   Local time: Wed 2025-11-05 00:39:17 EET
               Universal time: Tue 2025-11-04 22:39:17 UTC
                     RTC time: Tue 2025-11-04 22:39:17
                    Time zone: Europe/Sofia (EET, +0200)
    System clock synchronized: yes
                  NTP service: n/a
              RTC in local TZ: no

Why Choose libpam-oath?

  • 100% Free Software (GPL)
  • Works completely offline / self-hosted
  • Compatible with any standard TOTP app (FreeOTP, Aegis, andOTP, etc.)
  • Doesn’t depend on Google APIs or cloud services
  • Lightweight (just one PAM module and a text file)

Conclusion

Two-Factor Authentication doesn’t have to rely on Google’s ecosystem.
With OATH Toolkit and libpam-oath, you get a simple, private, and completely open-source way to harden your SSH server against brute-force and stolen-key attacks.

Once configured, even if an attacker somehow steals your SSH key or password, they can’t log in without your phone’s one-time code – making your system dramatically safer.

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Posted in Linux, Linux and FreeBSD Desktop, Security, System Administration | No Comments »

Protect Application servers against sql injects, redirection handling and click jacking with Haproxy load balancer

Tuesday, April 1st, 2025

 

Lets say you are a system administrator that has to manage haproxy Load Balancers for High Availability that are throwing traffic to a set of 4 Application servers and you do only do a traffic round robin load balancing seemless without modifying the sent traffic. The haproxies are used only to send the frontend traffic towards application machines and then the traffic is returned back via another set of haproxies.


As incoming requests to application frontend is crucial to be secure, i'll give in this article few options that can be turned on in haproxy to strenghten security of backend application (against "hackers" / script kiddies ).

Here is the a sample chunk of haproxy frontend backend configuration you can use in haproxy.cfg config file for the purpose.


  frontend Incoming_Frontend
           bind 10.10.150.8:80 ssl crt /etc/haproxy/certs/your-domain-cert.net_haproxy.pem ca-file /etc/haproxy/certs/CustomCompanyCA.crt verify optional
           mode http
                http-request del-header max-forwards
                http-response set-header X-Frame-Options sameorigin
                http-response replace-header Location http[s]*://[^/:]*[:]*[0-9]*(/.*) \1
              option httplog
              timeout client 600s
              log-format %ci:%cp\ [%t]\ %ft\ %b/%s\ %Tq/%Tw/%Tc/%Tr/%Tt\ %ST\ %B\ %CC\ %CS\ %tsc\ %ac/%fc/%bc/%sc/%rc\ %sq/%bq\ %hr\ %hs\ %{+Q}r

             default_backend bk_Incoming_Frontend

    backend bk_Incoming_Frontend
           mode http
           balance roundrobin
           timeout server 330s
           timeout connect 4s
           server bk_AppServer_01 10.10.250.40:8088 weight 1 check port 8088 on-marked-down shutdown-sessions
           server bk_AppServer02 10.40.251.30:8088 weight 1 check port 8088 on-marked-down shutdown-sessions
           server bk_AppServer03 10.50.252.40:8088 weight 1 check port 8088 on-marked-down shutdown-sessions
           server bk_AppServer04 10.80.253.50:8088 weight 1 check port 8088 on-marked-down shutdown-sessions

 

The configuration variables that would improve backend security is as so:

  mode http
                http-request del-header max-forwards
                http-response set-header X-Frame-Options sameorigin
                http-response replace-header Location http[s]*://[^/:]*[:]*[0-9]*(/.*) \1
              option httplog

Above config haproxy meaning explained is as follows: 

This HAProxy configuration is set up for handling HTTP traffic with some specific request and response modifications.

Let's go through each directive:

Breakdown of the Configuration:

  1. mode http

    • This tells HAProxy to operate in HTTP mode, meaning it understands and processes HTTP-specific directives (e.g., modifying headers, logging, etc.).

  2. http-request del-header max-forwards

    • This removes the Max-Forwards header from incoming HTTP requests.

    • The Max-Forwards header is used in TRACE or OPTIONS requests to limit the number of hops a request can take.

    • Removing it may help prevent some types of request-loop abuse or simplify routing.

  3. http-response set-header X-Frame-Options sameorigin

    • This sets the X-Frame-Options header in HTTP responses to sameorigin.

    • Purpose: Prevents clickjacking attacks by ensuring that the page can only be embedded in a frame if it’s from the same origin (not by third-party sites).

      For those who don't know Clickjacking is The malicious practice of manipulating a website user's activity by concealing hyperlinks beneath legitimate clickable content, thereby causing the user to perform actions of which they are unaware. For example you click a payment button on a website from a decoy website but instead of paying to the real target site your money are sent to a malicious user's bank account..

  4. http-response replace-header Location http[s]*://[^/:]*[:]*[0-9]*(/.*) \1

    • This modifies the Location header in HTTP responses.

    • It strips out the scheme (http:// or https://), domain, and port, leaving only the path.

    • Example:

      • Before: Location: https://example.com:8080/path/to/resource

      • After: Location: /path/to/resource

    • This ensures that redirects remain relative instead of absolute, which can help in reverse proxy setups.

  5. option httplog

    • Enables detailed logging for HTTP traffic.

    • Logs will include request method, URL, response status, and other useful details for debugging and monitoring.

Purpose of This Configuration:

  • Security:

    • Removing Max-Forwards helps mitigate abuse.

    • X-Frame-Options: sameorigin prevents clickjacking.

  • Redirection Handling:

    • Ensures the backend does not expose internal hostnames or ports in redirects.

  • Logging:

    • Enables HTTP-specific logging for better monitoring and debugging.

This setup is typical for a reverse proxy scenario where HAProxy is fronting backend services while enforcing security measures and keeping responses clean.

What we learned ?

In this short article, we've learned about how to imrpove application security with simple haproxy load balancer by removing Max-forwards (limitation of max hops traffic could have until reaching the destination), the X-Frame-Options that prevents clickjacking and using Redirection Handling to make sure backend does not expose internal  hostnames or ports used in redirects.

Any other meaningful protection options and hints whether proxying traffic with haproxy are mostly welcome to har about in commects section. If you know such help others learn by sharing.

Tags: , , , , , , , , ,
Posted in Haproxy, Linux, System Administration, Web and CMS | No Comments »

Enable Debian Linux automatic updates to keep latest OS Patches / Security Up to Date

Monday, January 13th, 2025

Enable Debian Linux automatic updates to keep latest OS Patches / Security Up to Date

Debian: Entenda a Importância Para o Mundo GNU/LINUX

I'm not a big fan of automatism on GNU / Linux as often using automatic updates could totally mess things especially with a complex and a bit chatic OS-es like is Linux nowadays. 
Nevertheless as Security is becoming more and more of a problem especially the browser security, having a scheduled way to apply updates like every normal modern Windows and MAC OS as an option is becoming essential to have a fully manageble Operating system.

As I use Debian GNU / Linux for desktop for my own personal computer and I have already a lot of Debian servers, whose OS minor level and package version maintenance takes up too big chunk of my time (a time I could dedicated to more useful activities). Thus I found it worthy at some cases to trigger Debian's way to keep the OS and security at a present level, the so called Debian "unattended upgrades".

In this article, I'll explain how to install and Enable Automatic (" Unattended " ) Updates on Debian, with the hope that other Debian users might start benefiting from it.
 

Pros of  enabling automatic updates, are:

  • Debian OS Stay secure without constant monitoring.
  • You Save much time by letting your system handle updates.
  • Presumably Enjoying more peace of mind, knowing your system is more protected.

Cons of enabling automatic updates:

  • Some exotic and bad maintained packages (might break after the update)
  • Customizations made on the OS /etc/sysctl.conf or any other very custom server configs might disappear or not work after the update
  • At worst scenario (a very rare but possible case) OS might fail to boot after update 🙂

Regular security updates patch vulnerabilities that could otherwise be exploited by attackers, which is especially important for servers and systems exposed to the internet, where threats evolve constantly.

1. Update Debian System to latest

Before applying automatic updates making any changes, run apt to update package lists and upgrade any outdated packages,to have automatic updates for a smooth configuration process.

# apt update && apt upgrade -y

2. Install the Unattended-Upgrades deb Package 

# apt install unattended-upgrades -y

Reading package lists… Done
Building dependency tree… Done
Reading state information… Done
The following additional packages will be installed:
  distro-info-data gir1.2-glib-2.0 iso-codes libgirepository-1.0-1 lsb-release python-apt-common python3-apt python3-dbus python3-distro-info python3-gi
Suggested packages:
  isoquery python-apt-doc python-dbus-doc needrestart powermgmt-base
The following NEW packages will be installed:
  distro-info-data gir1.2-glib-2.0 iso-codes libgirepository-1.0-1 lsb-release python-apt-common python3-apt python3-dbus python3-distro-info python3-gi unattended-upgrades
0 upgraded, 11 newly installed, 0 to remove and 0 not upgraded.
Need to get 3,786 kB of archives.
After this operation, 24.4 MB of additional disk space will be used.
Do you want to continue? [Y/n]
 

 

# apt install apt-listchanges
Reading package lists… Done
Building dependency tree… Done
Reading state information… Done
The following package was automatically installed and is no longer required:
  linux-image-5.10.0-30-amd64
Use 'apt autoremove' to remove it.
The following additional packages will be installed:
  python3-debconf
The following NEW packages will be installed:
  apt-listchanges python3-debconf
0 upgraded, 2 newly installed, 0 to remove and 0 not upgraded.
Need to get 137 kB of archives.
After this operation, 452 kB of additional disk space will be used.
Do you want to continue? [Y/n]
Get:1 http://deb.debian.org/debian bookworm/main amd64 python3-debconf all 1.5.82 [3,980 B]
Get:2 http://deb.debian.org/debian bookworm/main amd64 apt-listchanges all 3.24 [133 kB]
Fetched 137 kB in 0s (292 kB/s)
Preconfiguring packages …
Deferring configuration of apt-listchanges until /usr/bin/python3
and python's debconf module are available
Selecting previously unselected package python3-debconf.
(Reading database … 84582 files and directories currently installed.)
Preparing to unpack …/python3-debconf_1.5.82_all.deb …
Unpacking python3-debconf (1.5.82) …
Selecting previously unselected package apt-listchanges.
Preparing to unpack …/apt-listchanges_3.24_all.deb …
Unpacking apt-listchanges (3.24) …
Setting up python3-debconf (1.5.82) …
Setting up apt-listchanges (3.24) …

Creating config file /etc/apt/listchanges.conf with new version

 

Example config for apt-listchanges would be like:

# vim /etc/apt/listchanges.conf
[apt]
frontend=pager
email_address=root
confirm=0
save_seen=/var/lib/apt/listchanges.db
which=both

3. Enable Automatic unattended upgrades

Once installed, enable automatic updates with the following command, which will prompt asking if you want to enable automatic updates. Select Yes and press Enter, which will confirm that the unattended-upgrades service is active and ready to manage updates for you.

# dpkg-reconfigure unattended-upgrades

Configure-Unattended-Upgrades-on-Debian_Linux-dpkg-reconfigure-screenshot

Or non-interactively by running command:

# echo unattended-upgrades unattended-upgrades/enable_auto_updates boolean true | debconf-set-selections
dpkg-reconfigure -f noninteractive unattended-upgrades


4. Set the Schedule for Automatic Updates on Debian

By default, unattended-upgrades runs daily, to verify or modify the schedule, check the systemd timer:

# sudo systemctl status apt-daily.timer
# sudo systemctl status apt-daily-upgrade.timer
# systemctl edit apt-daily-upgrade.timer

Current apt-daily.timer config as of Debian 12 (bookworm) is as follows

root@haproxy2:/etc/apt/apt.conf.d# cat  /lib/systemd/system/apt-daily.timer
[Unit]
Description=Daily apt download activities

[Timer]
OnCalendar=*-*-* 6,18:00
RandomizedDelaySec=12h
Persistent=true

[Install]
WantedBy=timers.target
root@haproxy2:/etc/apt/apt.conf.d#


 

# systemctl edit apt-daily-upgrade.timer

[Timer]
OnCalendar=
OnCalendar=03:00
RandomizedDelaySec=0

 

At Line  num 2 above is needed to reset (empty) the default value shown below in line  num 5.
Line 4 is needed to prevent any random delays coming from the defaults.


Now both timers should be active, if not, activate them with:

# systemctl enable –now apt-daily.timer
# systemctl enable –now apt-daily-upgrade.timer


These timers ensure that updates are checked and applied regularly, without manual intervention.

5.Test one time Automatic Updates on Debian works

To ensure everything is working, simulate an unattended upgrade with a dry run:

# unattended-upgrade –dry-run

 

You can monitor automatic updates by checking the logs.

# less /var/log/unattended-upgrades/unattended-upgrades.log

Log shows details of installed updates and any issues that occurred. Reviewing logs periodically can help you ensure that updates are being applied correctly and troubleshoot any problems.

6. Advanced Configuration Options

If you’re a power user or managing multiple systems, you might want to explore these additional settings in the configuration file:

# vim /etc/apt/apt.conf.d/50unattended-upgrades


Configure unattended-upgrades to send you an email whenever updates are installed.

Unattended-Upgrade::Mail "your-email-address@email-address.com";


Enable automatic reboots after kernel updates
by adding the line:

Unattended-Upgrade::Automatic-Reboot "true";

To schedule reboots after package upgrade is applied  at a specific time:

Unattended-Upgrade::Automatic-Reboot-Time "02:00";

Specify packages you don’t want to be updated by editing the Unattended-Upgrade::Package-Blacklist section in the configuration file.

 

Here is alternative way to configure the unattended upgrade, by using apt configuration options:

# vim /etc/apt/apt.conf.d/02periodic

// Control parameters for cron jobs by /etc/cron.daily/apt-compat //


// Enable the update/upgrade script (0=disable)
APT::Periodic::Enable "1";


// Do "apt-get update" automatically every n-days (0=disable)
APT::Periodic::Update-Package-Lists "1";


// Do "apt-get upgrade –download-only" every n-days (0=disable)
APT::Periodic::Download-Upgradeable-Packages "1";


// Run the "unattended-upgrade" security upgrade script
// every n-days (0=disabled)
// Requires the package "unattended-upgrades" and will write
// a log in /var/log/unattended-upgrades
APT::Periodic::Unattended-Upgrade "1";


// Do "apt-get autoclean" every n-days (0=disable)
APT::Periodic::AutocleanInterval "21";


// Send report mail to root
//     0:  no report             (or null string)
//     1:  progress report       (actually any string)
//     2:  + command outputs     (remove -qq, remove 2>/dev/null, add -d)
//     3:  + trace on
APT::Periodic::Verbose "2";

If you have to simultaneously update multiple machines and you're on a limited connection line, configure download limits if you’re on a metered connection by setting options in /etc/apt/apt.conf.d/20auto-upgrades.

7. Stop Automatic Unattended Upgrade

Under some circumstances if it happens the unattended upgrades are no longer required and you want to revert back to manual package updates, to disable the updates you have to disable the unattended-upgrades service

# systemctl stop unattended-upgrades


8.  Stop an ongoing apt deb package set of updates applied on Debian server

Perhaps not often, but it might be you have run an automated upgrade and this has broke a server system or a service and for that reason you would like to stop the upcoming upgrade (some of whose might have started on other servers) immediately, to do so, the easiest way (not always safe thogh) is to kill the unattended-upgrades daemon.
 

# pkill –signal SIGKILL unattended-upgrades


Note that this a very brutal way to kill it and that might lead to some broken package update, that you might have to later fix manually.

If you have the unattended-upgrade process running on the OS in the process list backgrounded and you want to stop the being on the fly upgrade on the system more safely for the system, you can stop and cancel the ongoing apt upgrade  it by running the ncurses prompt interface, through dpkg-reconfigure

# dpkg-reconfigure unattended-upgrades


Then just select No, press Enter. In my case, this has promptly stopped the ongoing unattended upgrade that seemed blocked (at least as promptly as the hardware seemed to allow 🙂 ).

If you want to disable it for future, so it doesn't automatically gets enabled on next manual update, by some update script disable service as well.
 

# systemctl disable unattended-upgrades
…

 

Close up

That’s all ! Now, your Debian system will automatically handle security updates, keeping your system secure without you having to do a thing.
The same guide should be good for most Deb based distributions such as Ubuntu / Mint and there rest of other Debian derivative OS-es.
You’ve now set up a reliable way to ensure your system stays protected from vulnerabilities, but anyways it is a good practice to always login and check what the update has done to the system, otherwise expect the unexpected. 

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Posted in Computer Security, Curious Facts, Linux, Linux and FreeBSD Desktop, Linux on Laptops, Various | No Comments »

iSH, the best free SSH / Telnet client for iOS iPhone, iPad equivallent of MobaXterm and fully functional Alpine Linux emulator

Wednesday, February 8th, 2023

ish-linux-terminal-emulator-for-iphone-ipad-ios-logo-screenshoticon

Since few months I've switched my old BLU r1 HD Phone (a great old low budget phone for its price) to a friend's iPhone 10 ( X ) who gifted it for me. Coming from Android world, everyone who has experience with it is a pain in the ass as some of the Apps, which are into Google's play store does not have the same equivalent into Apple's install Package manager tool AppStore. Some of the crucial tools which I was interested as a freshly new migrated user from Android to iPhone was to have a decent SSH / Telnet client and Terminal, with which I can easily connect to my Linux servers both home and work. 

As Android Phone user, to connect and manage my SSH sessions I used most often some of the most popular Connectbot / SSHDroid / JuiceSSH.
On Android I've usually installed all of these tools but most frequently used Connectbot, which quickly become my favourite SSH client for Android over time.

The reasons why I really loved Connectbot and used it on Android OS in short:

  • It is Completely free
  • Ad-free
  • Open-source (too bad not Free software but still step better)
  • Copy and paste text between Applications
  • Customizable interface (i.e. font size, keyboard layout, SSH auth agent, etc.)


connectbot-android-ssh-remote-connect-client-screenshot

I've seen some people used and preferred Termius but never myself really liked this client, as it was including some Advertisements or for don't remember why reason.
Switching to iOS mobile operating system, of course was quite a shock especially the moment I found out the standard loved SSH Remote Client programs are used are not available or have only a paid version. Thus it took me quite a while of a research and googling until I found some decent stuff.

termius-ssh-telnet-client-ios-screenshot

Tried for a time with Termius as well but again, its Ads and lack of some functionality pissed me off, so I've moved on to Shelly.

shelly-iphone-ssh-telnet-client-ios-screenshot

Shelly is really not a bad tool but has limitation over the SSH sessions you can add and other limitations, which can only be unlocked with an "Upgrade", to its paid version, thus I decided after few weeks of attempts to make it my remote server management mobile tool for iPhone, I've dropped it off as well.

Then I found the Blink Shell App – Blink Shell is a professional, desktop grade terminal for iOS. As overall the tool is really great and is easy to use but again to have it used in its full power you need the paid version and until you pay for it every now and then you got interruption of your shell for some really annoying ads.
Thus even though I used it for a times this few tools with whom basicly you can do basic remote ssh / telnet session operations eventually,  started looking for a better SSH Client Free alternative for iPhone Users.

Then came a friend at home for a dinner my dear friend Milen (Static) and he show me iOS.
The moment I saw this tool I totally loved it, for its simplicity and its resemblance to a classical TTY Physical old Linux console I used back in the days and its ability to resemble easily any improved functionaltiy through simple screen (multiple session management) command tool or tmux.

Wait, what's iSH ? And why it is the Best SSH / Telnet client to manage your servers remotely on iOS Mobiles (iPhone and IPads) ? 

iSH is a project to get a Linux shell environment running locally on your iOS device, using a usermode x86 emulator.


In other wors iSH is Linux emulator with busybox and a package ports for many of the standard Linux tools you get by simple apt-get / yum or if I have to compare you get via the MobaXterm's advanced apt-cyg (Cygwin packages) tool capabilities.

Once iSH is installed it comes with pre-installed apk command line package management tool, with which you can install stuff like openssh-client / screen / tmux / mc (midnight commander) etc. apk, is an apt like command like tool which uses as a basis for installing its packages Alpine Linux repositories.
Alpine Linux is perhaps little known as it is not one of these main stream disributions, such as Fedora or Ubuntu, but for those more concerned about security  Alpine Linux is well known as it is a security-oriented, lightweight Linux distribution based on musl libc and busybox. What makes the Linux even more attractive and perhaps the reason why the iSH developers decided to use it as a basis for their iSH emulator is it being actively developed and its tightened security makes it a good compliment to the quite closed and security focused mobile platform iOS.

iSH is available straight from AppStore , so to use it install it and run it (it is really a great news that iOS does not require iphone to be jailbreak – ed, and it is an ordinary installable software straight from AppStore):
iSH, already comes with some of the standard programs you would expect in a Linux environment such as Vi, wget, zip / unzip, and tar.
However to fit it better for my use over ssh and improve its capabilities, as well as support and use multiple Virtual windows ssh, just like you do on a Linux xterm
run from ish shell: 

# apk add openssh-client
# apk add screen
# apk add vim
# apk add mc


ish-screenshot-terminal3-linux-emulator-iphone-alpine

ish-screenshot-terminal2-linux-emulator-iphone-alpine

ish-screenshot-terminal1-linux-emulator-iphone-alpine-linux

I also like to have a Midnight Commander and VIM Text editor installed out of the box to be able to move around in Ncurses interface through my iPhone.

ish-iphone-keyboard-key-shortcuts

Note that, just like most GNU / Linux distributions, iOS shell will run a normal bash shell.
From there on to use iSH as my default SSH client and enable my just installed GNU screen some Windowing beauty for readability whence I use the screen with multiple ssh logins to different servers as well make the screen Virtual consoles to have ability for scroll back and scroll up of console text to work, I do set up the following .screenrc inside my /home/iPhoneuser

The .screenrc to setup on the iSH to easify your work with screen is as follows:
 

# An alternative hardstatus to display a bar at the bottom listing the
# windownames and highlighting the current windowname in blue. (This is only
# enabled if there is no hardstatus setting for your terminal)
hardstatus on
hardstatus alwayslastline
hardstatus string "%{.bW}%-w%{.rW}%n %t%{-}%+w %=%{..G} %H %{..Y} %m/%d %C%a "
# Enable scrolling fix the annoying screen scrolling problem
termcapinfo xterm* ti@:te@
# Scroll up
bindkey -d "^[[5S" eval copy "stuff 5\025"
bindkey -m "^[[5S" stuff 5\025

# Scroll down
bindkey -d "^[[5T" eval copy "stuff 5\004"
bindkey -m "^[[5T" stuff 5\004

# Scroll up more
bindkey -d "^[[25S" eval copy "stuff \025"
bindkey -m "^[[25S" stuff \025

# Scroll down more
bindkey -d "^[[25T" eval copy "stuff \004"
bindkey -m "^[[25T" stuff \004

You can download the same .screenrc file from here straight with wget from the console:

# wget https://www.pc-freak.net/files/.screenrc


Run GNU screen manager

 

 # screen

You will end up with a screen session, to open a new session for Virtual Terminal use virtual keyboard from ISH and Press

CTRL + A + C

To open other Virtual Windows inside screen just press CTRL + A + C as many times as you need it, each session will appear ina small window on the down corner as you can see in screenshot

ish-terminal-with-screen-multiple-virtual-terminals-screenshot-iphone-ios

To move across the Screen unnamed 3 Virtual Windows 0 ash 1 ash and 2 ash use the Virtual keyboard

for next WIndow use key combination:
 

CTRL + A + N (where + is just to indicate you have to press them once after another and not actually press the + 🙂 )


For Previous Window use:

CTRL + A + P

Or use CTRL + A and type 

:number 3 (where number is the number of window)

The available iSH commands without adding any further packages which are part of the busybox install are as follows:

Available /bin/ directory commands:

arch  ash  base64  bbconfig  busybox  cat  chgrp  chmod  chown  conspy  cp  date  dd  df  dmesg  dnsdomainname  dumpkmap  echo  ed  egrep  false  fatattr  fdflush  fgrep  fsync  getopt  grep  gunzip  gzip  hostname  ionice  iostat  ipcalc  kbd_mode  kill  link  linux32  linux64  ln  login  ls  lzop  makemime  mkdir  mknod  mktemp  more  mount  mountpoint  mpstat  mv  netstat  nice  pidof  ping  ping6  pipe_progress  printenv  ps  pwd  reformime  rev  rm  rmdir  run-parts  sed  setpriv  setserial  sh  sleep  stty  su  sync  tar  touch  true  umount  uname  usleep  watch  zcat  


Available /usr/bin/ commands:    

awk  basename  beep  blkdiscard  bunzip2  bzcat  bzip2  cal  chvt  cksum  clear  cmp  comm  cpio  crontab  cryptpw  cut  dc  deallocvt  diff  dirname  dos2unix  du  dumpleases  eject  env  expand  expr  factor  fallocate  find  flock  fold  free  fuser  getconf  getent  groups  hd  head  hexdump  hostid  iconv  id  install  ipcrm  ipcs  killall  ldd  less  logger  lsof  lsusb  lzcat  lzma  lzopcat  md5sum  mesg  microcom  mkfifo  mkpasswd  nc  nl  nmeter  nohup  nproc  nsenter  nslookup  od  passwd  paste  patch  pgrep  pkill  pmap  printf  pscan  pstree  pwdx  readlink  realpath  renice  reset  resize  scanelf  seq  setkeycodes  setsid  sha1sum  sha256sum  sha3sum  sha512sum  showkey  shred  shuf  smemcap  sort  split  ssl_client  strings  sum  tac  tail  tee  test  time  timeout  top  tr  traceroute  traceroute6  truncate  tty  ttysize  udhcpc6  unexpand  uniq  unix2dos  unlink  unlzma  unlzop  unshare  unxz  unzip  uptime  uudecode  uuencode  vi  vlock  volname  wc  wget  which  whoami  whois  xargs  xxd  xzcat  yes  


If you're a maniac developer you can even use iSH, to do some programs development with vim with Python / Perl or PHP as these are available from the Alpine repositories and installable via a simple apk add packagename for security experts nmap and some security tools are also available but unfortunately not everything is still working as this project is in active development and iOS has some security limitations if OS is not ROOTED 🙂

Hence some of the packages you can install via apk manager will be failing actually.
There is a list of What works and what doesn't still on iSH on the project github wiki check it out here.

There is much more funny stuff you can do with it, and actually my quick research on how people use iSH on their phones lead me to some Videos talking about iOS and Ethical hacking etc, but I'll stop here as I dont have the time to dig deeper to it. 
If you know or have some good use of iSH or some other goody you are using as a hack please share in comments.

Enjoy ! 🙂

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Posted in Mobile Phone Apps & Games, System Administration | No Comments »

Install and configure rkhunter for improved security on a PCI DSS Linux / BSD servers with no access to Internet

Wednesday, November 10th, 2021

install-and-configure-rkhunter-with-tightened-security-variables-rkhunter-logo

rkhunter or Rootkit Hunter scans systems for known and unknown rootkits. The tool is not new and most system administrators that has to mantain some good security servers perhaps already use it in their daily sysadmin tasks.

It does this by comparing SHA-1 Hashes of important files with known good ones in online databases, searching for default directories (of rootkits), wrong permissions, hidden files, suspicious strings in kernel modules, commmon backdoors, sniffers and exploits as well as other special tests mostly for Linux and FreeBSD though a ports for other UNIX operating systems like Solaris etc. are perhaps available. rkhunter is notable due to its inclusion in popular mainstream FOSS operating systems (CentOS, Fedora,Debian, Ubuntu etc.).

Even though rkhunter is not rapidly improved over the last 3 years (its last Official version release was on 20th of Febuary 2018), it is a good tool that helps to strengthen even further security and it is often a requirement for Unix servers systems that should follow the PCI DSS Standards (Payment Card Industry Data Security Standards).

Configuring rkhunter is a pretty straight forward if you don't have too much requirements but I decided to write this article for the reason there are fwe interesting options that you might want to adopt in configuration to whitelist any files that are reported as Warnings, as well as how to set a configuration that sets a stricter security checks than the installation defaults. 

1. Install rkhunter .deb / .rpm package depending on the Linux distro or BSD

  • If you have to place it on a Redhat based distro CentOS / Redhat / Fedora

[root@Centos ~]# yum install -y rkhunter
…

 

  • On Debian distros the package name is equevallent to install there exec usual:

root@debian:~# apt install –yes rkhunter
…

  • On FreeBSD / NetBSD or other BSD forks you can install it from the BSD "World" ports system or install it from a precompiled binary.

freebsd# pkg install rkhunter
…

One important note to make here is to have a fully functional Alarming from rkhunter, you will have to have a fully functional configured postfix / exim / qmail whatever mail server to relay via official SMTP so you the Warning Alarm emails be able to reach your preferred Alarm email address. If you haven't installed postfix for example and configure it you might do.

– On Deb based distros 

[root@Centos ~]#yum install postfix


– On RPM based distros

root@debian:~# apt-get install –yes postfix


and as minimum, further on configure some functional Email Relay server within /etc/postfix/main.cf
 

# vi /etc/postfix/main.cf
relayhost = [relay.smtp-server.com]

2. Prepare rkhunter.conf initial configuration


Depending on what kind of files are present on the filesystem it could be for some reasons some standard package binaries has to be excluded for verification, because they possess unusual permissions because of manual sys admin monification this is done with the rkhunter variable PKGMGR_NO_VRFY.

If remote logging is configured on the system via something like rsyslog you will want to specificly tell it to rkhunter so this check as a possible security issue is skipped via ALLOW_SYSLOG_REMOTE_LOGGING=1. 

In case if remote root login via SSH protocol is disabled via /etc/ssh/sshd_config
PermitRootLogin no variable, the variable to include is ALLOW_SSH_ROOT_USER=no

It is useful to also increase the hashing check algorithm for security default one SHA256 you might want to change to SHA512, this is done via rkhunter.conf var HASH_CMD=SHA512

Triggering new email Warnings has to be configured so you receive, new mails at a preconfigured mailbox of your choice via variable
MAIL-ON-WARNING=SetMailAddress
 

# vi /etc/rkhunter.conf

PKGMGR_NO_VRFY=/usr/bin/su

PKGMGR_NO_VRFY=/usr/bin/passwd

ALLOW_SYSLOG_REMOTE_LOGGING=1

# Needed for corosync/pacemaker since update 19.11.2020

ALLOWDEVFILE=/dev/shm/qb-*/qb-*

# enabled ssh root access skip

ALLOW_SSH_ROOT_USER=no

HASH_CMD=SHA512

# Email address to sent alert in case of Warnings

MAIL-ON-WARNING=Your-Customer@Your-Email-Server-Destination-Address.com

MAIL-ON-WARNING=Your-Second-Peronsl-Email-Address@SMTP-Server.com

DISABLE_TESTS=os_specific


Optionally if you're using something specific such as corosync / pacemaker High Availability cluster or some specific software that is creating /dev/ files identified as potential Risks you might want to add more rkhunter.conf options like:
 

# Allow PCS/Pacemaker/Corosync
ALLOWDEVFILE=/dev/shm/qb-attrd-*
ALLOWDEVFILE=/dev/shm/qb-cfg-*
ALLOWDEVFILE=/dev/shm/qb-cib_rw-*
ALLOWDEVFILE=/dev/shm/qb-cib_shm-*
ALLOWDEVFILE=/dev/shm/qb-corosync-*
ALLOWDEVFILE=/dev/shm/qb-cpg-*
ALLOWDEVFILE=/dev/shm/qb-lrmd-*
ALLOWDEVFILE=/dev/shm/qb-pengine-*
ALLOWDEVFILE=/dev/shm/qb-quorum-*
ALLOWDEVFILE=/dev/shm/qb-stonith-*
ALLOWDEVFILE=/dev/shm/pulse-shm-*
ALLOWDEVFILE=/dev/md/md-device-map
# Needed for corosync/pacemaker since update 19.11.2020
ALLOWDEVFILE=/dev/shm/qb-*/qb-*

# tomboy creates this one
ALLOWDEVFILE="/dev/shm/mono.*"
# created by libv4l
ALLOWDEVFILE="/dev/shm/libv4l-*"
# created by spice video
ALLOWDEVFILE="/dev/shm/spice.*"
# created by mdadm
ALLOWDEVFILE="/dev/md/autorebuild.pid"
# 389 Directory Server
ALLOWDEVFILE=/dev/shm/sem.slapd-*.stats
# squid proxy
ALLOWDEVFILE=/dev/shm/squid-cf*
# squid ssl cache
ALLOWDEVFILE=/dev/shm/squid-ssl_session_cache.shm
# Allow podman
ALLOWDEVFILE=/dev/shm/libpod*lock*

 

3. Set the proper mirror database URL location to internal network repository

 

Usually  file /var/lib/rkhunter/db/mirrors.dat does contain Internet server address where latest version of mirrors.dat could be fetched, below is how it looks by default on Debian 10 Linux.

root@debian:/var/lib/rkhunter/db# cat mirrors.dat 
Version:2007060601
mirror=http://rkhunter.sourceforge.net
mirror=http://rkhunter.sourceforge.net

As you can guess a machine that doesn't have access to the Internet neither directly, neither via some kind of secure proxy because it is in a Paranoic Demilitarized Zone (DMZ) Network with many firewalls. What you can do then is setup another Mirror server (Apache / Nginx) within the local PCI secured LAN that gets regularly the database from official database on http://rkhunter.sourceforge.net/ (by installing and running rkhunter –update command on the Mirror WebServer and copying data under some directory structure on the remote local LAN accessible server, to keep the DB uptodate you might want to setup a cron to periodically copy latest available rkhunter database towards the http://mirror-url/path-folder/)

# vi /var/lib/rkhunter/db/mirrors.dat

local=http://rkhunter-url-mirror-server-url.com/rkhunter/1.4/


A mirror copy of entire db files from Debian 10.8 ( Buster ) ready for download are here.

Update entire file property db and check for rkhunter db updates

 

# rkhunter –update && rkhunter –propupdate

[ Rootkit Hunter version 1.4.6 ]

Checking rkhunter data files…
  Checking file mirrors.dat                                  [ Skipped ]
  Checking file programs_bad.dat                             [ No update ]
  Checking file backdoorports.dat                            [ No update ]
  Checking file suspscan.dat                                 [ No update ]
  Checking file i18n/cn                                      [ No update ]
  Checking file i18n/de                                      [ No update ]
  Checking file i18n/en                                      [ No update ]
  Checking file i18n/tr                                      [ No update ]
  Checking file i18n/tr.utf8                                 [ No update ]
  Checking file i18n/zh                                      [ No update ]
  Checking file i18n/zh.utf8                                 [ No update ]
  Checking file i18n/ja                                      [ No update ]
 

rkhunter-update-propupdate-screenshot-centos-linux


4. Initiate a first time check and see whether something is not triggering Warnings

# rkhunter –check

rkhunter-checking-for-rootkits-linux-screenshot

As you might have to run the rkhunter multiple times, there is annoying Press Enter prompt, between checks. The idea of it is that you're able to inspect what went on but since usually, inspecting /var/log/rkhunter/rkhunter.log is much more easier, I prefer to skip this with –skip-keypress option.

# rkhunter –check  –skip-keypress


5. Whitelist additional files and dev triggering false warnings alerts


You have to keep in mind many files which are considered to not be officially PCI compatible and potentially dangerous such as lynx browser curl, telnet etc. might trigger Warning, after checking them thoroughfully with some AntiVirus software such as Clamav and checking the MD5 checksum compared to a clean installed .deb / .rpm package on another RootKit, Virus, Spyware etc. Clean system (be it virtual machine or a Testing / Staging) machine you might want to simply whitelist the files which are incorrectly detected as dangerous for the system security.

Again this can be achieved with

PKGMGR_NO_VRFY=

Some Cluster softwares that are preparing their own /dev/ temporary files such as Pacemaker / Corosync might also trigger alarms, so you might want to suppress this as well with ALLOWDEVFILE

ALLOWDEVFILE=/dev/shm/qb-*/qb-*


If Warnings are found check what is the issue and if necessery white list files due to incorrect permissions in /etc/rkhunter.conf .

rkhunter-warnings-found-screenshot

Re-run the check until all appears clean as in below screenshot.

rkhunter-clean-report-linux-screenshot

Fixing Checking for a system logging configuration file [ Warning ]

If you happen to get some message like, message appears when rkhunter -C is done on legacy CentOS release 6.10 (Final) servers:

[13:45:29] Checking for a system logging configuration file [ Warning ]
[13:45:29] Warning: The 'systemd-journald' daemon is running, but no configuration file can be found.
[13:45:29] Checking if syslog remote logging is allowed [ Allowed ]

To fix it, you will have to disable SYSLOG_CONFIG_FILE at all.
 

SYSLOG_CONFIG_FILE=NONE

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Posted in Computer Security, Educational, Linux, System Administration | 2 Comments »

Linux: Howto Fix “N: Repository ‘http://deb.debian.org/debian buster InRelease’ changed its ‘Version’ value from ‘10.9’ to ‘10.10’” error to resolve apt-get release update issue

Friday, August 13th, 2021

Linux's surprises and disorganization is continuously growing day by day and I start to realize it is becoming mostly impossible to support easily this piece of hackware bundled together.
Usually so far during the last 5 – 7 years, I rarely had any general issues with using:

 apt-get update && apt-get upgrade && apt-get dist-upgrade 

to raise a server's working stable Debian Linux version packages e.g. version X.Y to verzion X.Z (for example up the release from Debian Jessie from 8.1 to 8.2). 

Today I just tried to follow this well known and established procedure that, of course nowdays is better to be done with the newer "apt" command instead with the legacy "apt-get"
And the set of 
 

# apt-get update && apt-get upgrade && apt-get dist-upgrade

 

has triggered below shitty error:
 

root@zabbix:~# apt-get update && apt-get upgrade
Get:1 http://security.debian.org buster/updates InRelease [65.4 kB]
Get:2 http://deb.debian.org/debian buster InRelease [122 kB]
Get:3 http://security.debian.org buster/updates/non-free Sources [688 B]
Get:4 http://repo.zabbix.com/zabbix/5.0/debian buster InRelease [7096 B]
Get:5 http://security.debian.org buster/updates/main Sources [198 kB]
Get:6 http://security.debian.org buster/updates/main amd64 Packages [300 kB]
Get:7 http://security.debian.org buster/updates/main Translation-en [157 kB]
Get:8 http://security.debian.org buster/updates/non-free amd64 Packages [556 B]
Get:9 http://deb.debian.org/debian buster/main Sources [7836 kB]
Get:10 http://repo.zabbix.com/zabbix/5.0/debian buster/main Sources [1192 B]
Get:11 http://repo.zabbix.com/zabbix/5.0/debian buster/main amd64 Packages [4785 B]
Get:12 http://deb.debian.org/debian buster/non-free Sources [85.7 kB]
Get:13 http://deb.debian.org/debian buster/contrib Sources [42.5 kB]
Get:14 http://deb.debian.org/debian buster/main amd64 Packages [7907 kB]
Get:15 http://deb.debian.org/debian buster/main Translation-en [5968 kB]
Get:16 http://deb.debian.org/debian buster/main amd64 Contents (deb) [37.3 MB]
Get:17 http://deb.debian.org/debian buster/contrib amd64 Packages [50.1 kB]
Get:18 http://deb.debian.org/debian buster/non-free amd64 Packages [87.7 kB]
Get:19 http://deb.debian.org/debian buster/non-free Translation-en [88.9 kB]
Get:20 http://deb.debian.org/debian buster/non-free amd64 Contents (deb) [861 kB]
Fetched 61.1 MB in 22s (2774 kB/s)
Reading package lists… Done
N: Repository 'http://deb.debian.org/debian buster InRelease' changed its 'Version' value from '10.9' to '10.10'
…


As I used to realize nowdays, as Linux started originally as 'Hackers' operating system, its legacy is just one big hack and everything from simple maintenance up to the higher and more sophisticated things requires a workaround 'hack''.

 

This time the hack to resolve error:
 

N: Repository 'http://deb.debian.org/debian buster InRelease' changed its 'Version' value from '10.9' to '10.10'


is up to running cmd:
 

debian-server:~# apt-get update –allow-releaseinfo-change
Поп:1 http://ftp.de.debian.org/debian buster-backports InRelease
Поп:2 http://ftp.debian.org/debian stable InRelease
Поп:3 http://security.debian.org stable/updates InRelease
Изт:5 https://packages.sury.org/php buster InRelease [6837 B]
Изт:6 https://download.docker.com/linux/debian stretch InRelease [44,8 kB]
Изт:7 https://packages.sury.org/php buster/main amd64 Packages [317 kB]
Игн:4 https://attic.owncloud.org/download/repositories/production/Debian_10  InRelease
Изт:8 https://download.owncloud.org/download/repositories/production/Debian_10  Release [964 B]
Изт:9 https://packages.sury.org/php buster/main i386 Packages [314 kB]
Изт:10 https://download.owncloud.org/download/repositories/production/Debian_10  Release.gpg [481 B]
Грш:10 https://download.owncloud.org/download/repositories/production/Debian_10  Release.gpg
  Следните подписи са невалидни: DDA2C105C4B73A6649AD2BBD47AE7F72479BC94B
Грш:11 https://ookla.bintray.com/debian generic InRelease
  403  Forbidden [IP: 52.39.193.126 443]
Четене на списъците с пакети… Готово
N: Repository 'https://packages.sury.org/php buster InRelease' changed its 'Suite' value from '' to 'buster'
W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: https://download.owncloud.org/download/repositories/production/Debian_10  Release: 
…

apt-get-update-allow-releaseinfo-change-debian-linux-screenshot

Onwards to upgrade the system up to the latest .deb packages, as usual run:

# apt-get -y update && apt-get upgrade -y
…

 

and updates should be applied as usual with some prompts on whether you prefer to keep or replace existing service configuration and some information on some general changes that might affect your installed services. In a few minutes and few prompts hopefully your Debian OS should be up to the latest stable.

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Posted in Linux, System Administration, Various | No Comments »

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