GlassWire is a popular network monitoring application (without Linux support) that helps you track data usage, unusual network activities, malicious network access, and more.

I wish it supported Linux, but for now it only works on Windows and Android.

For Linux, we don’t have a full-fledged GUI-based application that helps us monitor the network in Linux.

However, I recently came across “Portmaster”, an open-source network monitor available for Linux and other platforms. Interestingly, it offers some of the same capabilities seen with Glasswire, with a few extras.

Note that this is not exactly a replacement for “GlassWire” but a potential alternative in the making.

Here I will share more details about it.

Safing Portmaster (or simply “Portmaster”) is in its early stages of development (Alpha). We present it here because it aims to offer something new to Linux users.

Although it worked well in our quick tests, you can expect some issues.

Portmaster: open source application to monitor computer network connection

Harbor master by Security is an open source GUI program available for Windows and Linux.

You can track every connection made through the apps and services used in your Linux distribution.

It is completely free and open-source software that aims to earn money using its paid VPN service (SPN), which uses onion encryption (inspired by Tor) to route your connections from destinations while keeping your identity private.

Paid VPN is part of the tool, but it is also in alpha testing.

Even if you download things from your device, it tracks them and provides you with detailed information regarding the domain, IP address, encryption status, protocol, and the ability to block future connections if needed.

port master network monitor

You also get multiple capabilities to manage network connections, add filter lists, rules, and other advanced options.

Portmaster gives you an overview of all connections per app/service and also allows you to view data associated with an individual app.

port master connection details

It supports many useful features including real-time network monitoring.

Portmaster Features

port master firewall network

Portmaster is not just a simple network connection monitor, it also gives you great control to enforce secure DNS and filter your network connections for better security.

Some key features include:

  • Network monitor overview to summarize the connections of the whole system.
  • Provide debug information for each app login history.
  • Ability to block a domain from the connection list.
  • Keep offline connection history.
  • Manage P2P connections.
  • Ability to block incoming connections.
  • Ability to add outbound rules to easily manage network connections.
  • Add a list of filters to easily block connections you don’t want. For example, preventing NSFW domains from loading on your network.
  • Choose from different secure DNS servers (Cloudflare as preferred default)
  • Statistics on network connections, connected destinations, affected countries, allowed and blocked connections.

In addition to the mentioned features, you’ll find granular controls to prompt for network connections (block/allow), customize your privacy filter, choose a different DNS, inspect DNS queries for established connections, and much more.

Install Portmaster on Linux

Portmaster is officially supported for Ubuntu and Fedora with .deb and .rpm packages available.

You can download the package from its official site to try on a supported Linux distribution.

The installation documentation gives you more detailed steps for Arch Linux and other Linux distributions.

You can also read more about it in his GitHub page.


Portmaster is certainly an interesting addition to the Linux and open-source world. It could become the one tool everyone uses to monitor and secure networks while improving their online privacy.

The feature set is promising, but whether it can replace proprietary network monitors like “GlassWire” is another story for the future.

What do you think of Portmaster? Please let me know your thoughts in the comments below.