RFC 5880: Bidirectional Forwarding Detection (BFD)
RFC 7419: Common Interval Support in BFD
Bidirectional Forwarding Detection (BFD) is a lightweight and low-overhead protocol designed to provide rapid failure detection and notification in IP networks. BFD operates independently from the routing protocol and offers better efficiency compared to simply reducing HELLO intervals. In EIGRP, BFD plays a crucial role in enhancing network reliability and responsiveness.
Key Features of BFD
- Independence: BFD operates independently from the routing protocol, allowing it to detect failures and report them rapidly.
- Efficiency: BFD offers better efficiency than reducing HELLO intervals, as it focuses solely on failure detection.
- Layer 2.5: BFD works at Layer 2.5, making it a versatile protocol for various networking scenarios.
- EIGRP Integration: EIGRP can register with BFD when configured, ensuring that failure detection aligns seamlessly with EIGRP's operation.
BFD Versions
BFD has two main versions, each with its own characteristics:
- Version 0: Supports echo mode with asymmetry.
- Version 1: Supports echo mode with symmetry.
Configuration and Verification
To configure and verify BFD in the context of EIGRP, use the following commands:
bfd interval [ms] min_rx [ms] multiplier [interval-multiplier]: Configures BFD parameters, including the desired interval, minimum receive interval, and multiplier.show bfd neighbors [detail]: Displays detailed information about BFD neighbors and their status.show ip[v6] eigrp interfaces [detail]: Shows detailed information about EIGRP interfaces, including BFD-related settings.
BFD, as specified in RFC 5880 and RFC 7419, is a critical component in enhancing the reliability and responsiveness of EIGRP networks. It provides rapid failure detection, helping networks adapt to changing conditions swiftly.