How vagrant-libvirt Plugin Deals with Duplicate Subnets
The author describes how the `vagrant-libvirt` plugin unexpectedly crashes when an existing libvirt virtual network, even with a different name, shares the same IP subnet as the intended management network, leading to a frustrating half-day debugging session.
MAIN POINTS
- `vagrant-libvirt` can crash mysteriously under a subnet conflict.
- An existing libvirt network used the same IP range as the management network.
- The issue appeared while using `netlab` and Vagrant to manage KVM virtual machines.
- The author spent hours debugging what turned out to be a simple configuration mistake.
TAKEAWAYS
- Matching IP subnets across virtual networks can trigger unexpected failures.
- Naming differences do not prevent libvirt network conflicts.
- Infrastructure tools may fail in ways that look like software bugs.
- Careful network planning can save significant debugging time.