PyBGP

An attempt to write the BGP router

PyBGP is Python / Asyncio-based BGP implementation. It fully supports the Finite State Machine and can open and maintain connectivity to BGP peers in either passive or active mode. Connection collision detection is already implemented, so it can drop the less desired connection if two form simultaneously. It can support connectivity to multiple peers at the same time.

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Features

Already implemented:

• Finite State Machine - running as a coroutine
• Event system with message queuing
• TX/RX Network IO - running as a coroutine
• Timers - connect_retry, hold, keepalive
• Support for parsing and creating BGP messages
• Passive and Active connectivity with a collision detection mechanism
• Ability to maintain simultaneous connectivity with multiple peers

Work in progress:

• BGP Updates

Next steps:

• Implementing fully functional Route Reflector

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Examples

Communication with three BGP peers

Finite State Machine establishing connectivity by using an active TCP connection

Finite State Machine establishing connectivity by using a passive TCP connection

Finite State Machine choosing passive over active connection due to peer's higher BGP ID