Nebula is a scalable, decentralized overlay networking tool designed to create secure, encrypted peer-to-peer connections between distributed hosts. By utilizing a certificate-based identity authority, it enables the construction of private communication fabrics across disparate physical infrastructures, such as multiple cloud providers or on-premises data centers, without requiring central authentication servers.
The project distinguishes itself through a zero-trust architecture that enforces granular, policy-driven firewall filtering based on certificate-derived group memberships. It facilitates direct connectivity between nodes located behind restrictive firewalls and network boundaries by employing a sophisticated discovery protocol, relay nodes, and persistent keep-alive signaling to maintain stable tunnels.
Beyond its core connectivity features, the software provides a comprehensive suite of operational tools for network management and observability. This includes built-in diagnostic utilities for troubleshooting, support for exporting performance metrics to external monitoring systems, and integrated hostname resolution. The system also manages the full lifecycle of cryptographic identities, allowing for secure credential issuance and rotation to maintain network trust.
