GlassWire is a popular network monitoring app (with no support for Linux) that helps you track data usage, unusual network activity, malicious access to the network, and more.
I wish it supports Linux, but for now, it only works on Windows and Android.
For Linux, we do not have a full-fledged GUI-based application like GlassWire that helps us monitor the network in Linux.
However, I recently stumbled upon “Portmaster”, an open-source network monitor available for Linux and other platforms. Interestingly, it offers some of the same abilities as seen with Glasswire, with some extras.
Note that it is not exactly a replacement for “GlassWire” but a potential alternative in the making.
Here, I shall share more details about it.
Note
Safing Portmaster (or simply ‘Portmaster’) is in its early stages of development (Alpha). We feature it here, considering it aims to offer something new to Linux users.
While it worked fine in our quick tests, you can expect issues with it.
Portmaster: Open-Source App to Monitor Computer’s Network Connection

Portmaster by Safing is an open-source GUI program available for Windows and Linux.
You can track every connection being made through the applications and services used in your Linux distribution.
It is an entirely free and open-source software that aims to make money using its paid VPN service (SPN), which uses onion-encryption (inspired by Tor) to route your connections from through destinations keeping your identity private.
The paid VPN is a part of the tool, but it is also in the alpha testing stage.
Even if you download things from your terminal, it tracks them and provides you the detailed information regarding the domain, IP, encryption status, protocol, and the option to block future connections if needed.

You also get several abilities to manage the network connections, add filter lists, rules, and some other advanced options.
Portmaster gives you an overview of all the connections per application/service and also lets you view the data associated with an individual application.

It supports numerous useful features that include real-time network monitoring.
Features of Portmaster

Portmaster is not just a simple network connection monitor, it also gives you great control to enforce a secure DNS, and filter your network connections for best security.
Some key features include:
- Network monitor overview to sum up connections from the entire system.
- Provide debug information for every app connection history.
- Ability to block a domain from the connection list.
- Retain connection history offline.
- Manage P2P connections.
- Ability to block incoming connections.
- Option to add outgoing rules to manage the network connections easily.
- Add a filter list to easily block connections that you do not want. For instance, preventing NSFW domains to load on your network.
- Choose from different secure DNS servers (Cloudflare as the preferred default)
- Stats about network connections, destinations connected, countries involved, allowed, and blocked connections.
In addition to the mentioned features, you will find fine-grained controls to get prompts for network connections (block/allow), customize your privacy filter, choose a different DNS, inspect DNS requests for the connections made, and so 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 website to try on a supported Linux distribution.
The installation documentation gives you more details about the steps for Arch Linux and other Linux distributions.
You can also explore more about it in its GitHub page.
Wrapping Up
Portmaster is certainly an interesting addition to the Linux and open-source world. It could become the one tool that everyone uses to monitor, and secure networks while enhancing their online privacy.
The feature set is promising, but whether it can replace proprietary network monitors like “GlassWire” is another story to be unraveled in the future.
What do you think about Portmaster? Please let me know your thoughts in the comments below.
Opensnitch and douane do these things.
There is, too vnstat-client, It’s a GUI client for the vnStat utility.
Its design is very good and easy to use.
https://github.com/Hulxv/vnstat-client
That’s interesting to know! Thanks for the suggestion!
Thank you for the tip regarding this tool. It looks great. How is it possible to stop that it starts up automatically on booting the system? I could not find anything in the options and it is not listed in the startup apps.
You can follow the commands mentioned here to disable it as a startup app:
https://docs.safing.io/portmaster/install/linux#starting-and-stopping-the-portmaster
Thank you, Ankush! Now I see it too :) : sudo systemctl disable portmaster
I could run the command “sudo systemctl disable portmaster”. The core service does not start automatically again but the app still starts up … Any way to stop it from automatically starting it on booting the OS?
IMO there are better GlassWire alternatives on Linux, albeit across multiple applications.
picosnitch – bandwidth graphs, hashes and VirusTotal support (GlassWire’s best feature and missing from Portmaster) https://github.com/elesiuta/picosnitch
Pi.Alert – network device detection (also missing from Portmaster) https://github.com/pucherot/Pi.Alert
Flatseal – block network access for applications, better user experience and more effective since Flatpaks are sandboxed, however with the obvious downside of only working with Flatpaks (but I don’t feel the need to block anything from my distro’s official repo anyways) https://github.com/tchx84/Flatseal
I wasn’t aware of the first two options. Thanks for the suggestion! :)
As I mentioned, Portmaster is not an exact replacement for GlassWire, nothing is actually (when it comes to Linux).
I’d like Portmaster to evolve as an all-in-one option, instead of using multiple tools. Let’s hope for the best!
Regarding application firewall I suggest use OpenSnitch.
https://github.com/evilsocket/opensnitch
Sounds exciting! Thanks for the recommendation!