First Look at Portmaster, an Open Source Cross-Platform Network Monitor
harbor master is a free, open-source cross-platform network activity monitor available in an early version for Windows and Ubuntu and Fedora Linux distributions.
Portmaster combines traditional network activity monitoring with additional features, such as the ability to enforce the use of secure DNS or automatic blocking of advertising, trackers and malicious hosts using filter lists, which are commonly used by ad blockers.
Portmaster is free to use, which usually leads to wondering how the development is funded. The developers behind Portmaster reveal information about it on the project’s official website. Basically what they plan to do is use a freemium model. Portmaster will be free for all users but additional services, a VPN is specifically mentioned, are available to users who sign up for them. Money is earned from this, which is used to fund development.
Harbor Master: First Look
An alpha version of Portmaster is available for Windows and Linux. It is released for testing and development purposes at the time. Alpha software may contain bugs and problems and should not be installed on production machines.
The development team notes that the alpha tag is “more about missing features than instability” of the app. Features planned for the first beta include import and export options, support for custom filter lists, crypto-signed updates, and full device network monitor.
Installation is simple under Windows; a reboot is required to complete the installation process. The interface is well designed and modern. The main page lists recent network activity, including the total number of connections and the percentage of connections allowed and blocked.
Clicking on an app or service in the network activity list displays details, including name and path, and information about every connection that has been made in the past.
Each connection is listed with the target, whether the data was encrypted, the IP addresses and the countries of the IP addresses.
Parameters can be set for each individual application. Besides blocking all network activity, users can change several connection-specific options. To name a few:
- Switch between default network actions: allow, block, invite.
- Block Internet or LAN connectivity.
- Block P2P/direct connections
- Block incoming connections.
- Configure outbound rules.
- Apply filter lists, e.g. ad and tracker blocking, malware hosts
All of these can be set globally, so preferences apply by default to all apps and services. Override options are available for individual applications.
The All Apps section lists all apps with current and past network activity. A search function is available to quickly find applications in the list. You can select any app or service to change the default network behavior.
The premium SPN feature, Safing Privacy Network, is also included in alpha. The service is inspired by Tor, as it routes connections through multiple network hops for better privacy. The main difference with VPNs is the multi-hop architecture. Some VPNs, NordVPN for example, also support multiple connections, but these are generally not designed to hide information such as destination from each other.
Portmaster is a promising network monitor: it is free, open source and available for different platforms. Windows and Linux versions are available, and a Mac version is planned for the future. The interface is well designed and although some features are missing, it is already functional.
It’s too early to tell how it will compare to other network monitors and firewalls such as Glasswire, Windows Firewall Control or SimpleWall.
Now you: are you using a third-party network monitor or firewall?