netlab release 26.05 is out. I’ll write about its highlights tomorrow; today, I want to focus on one of its breaking changes: netlab no longer works with Python 3.8 (which reached end-of-life in October 2024), so you can no longer install it on a vanilla Ubuntu 20.04 (which reached end of standard support a year ago).

We wanted to get rid of old Python versions for ages, but never did because Ubuntu 20.04 shipped with Python 3.8, and many netlab early adopters installed it on Ubuntu 20.04 (and the last thing a networking engineer wants is wasting time with upgrades, right?).

However, the latest containerlab release (0.75.0) stopped working on ancient container software, and that was the last nudge we needed to rip off that bandaid.

The networklab package in release 26.05 is thus defined to run on Python 3.10 and above. You might be able to continue using netlab with Ubuntu 20.04 if you manage to install Python 3.10 on that system. If you decide to do that, disable the containerlab version check with netlab defaults 'providers.clab.probe=[]' to continue working with older containerlab releases that run on Ubuntu 20.04 (at least until containerlab developers fix this issue).

However, don’t rush with upgrading your old ancient netlab servers. We’re still discovering quirks in Ubuntu 24.04 (primarily different QEMU defaults and edge cases) and ironing them out. On the other hand, we’d love to have more people reporting those quirks, so if you don’t mind opening an issue or two, please do the upgrade ;)

Upgrading or Starting from Scratch?

• To upgrade your netlab installation, execute pip3 install --upgrade networklab.
• New to netlab? Start with the Getting Started document and the installation guide.
• Need help? Open a discussion or an issue in netlab GitHub repository.