receives a Down status notification from the remote system, the session state on the local system
changes to Init.
Figure 9. Session State Changes
Important Points to Remember
• BFD for line card ports is hitless, but is not hitless for VLANs because they are instantiated on the RPM.
• The Dell Networking OS supports a maximum of 100 sessions per BFD agent. Each linecard processor
has a BFD Agent, so the limit translates to 100 BFD sessions per linecard.
• Enable BFD on both ends of a link.
• Demand mode, authentication, and the Echo function are not supported.
• BFD is not supported on multi-hop and virtual links.
• Protocol Liveness is supported for routing protocols only.
• The Dell Networking OS supports only OSPF, OSPFv3, BGP, and VRRP protocols as BFD clients.
Bidirectional Forwarding Detection (BFD)
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