Deployment Guide

Session State Changes
The following illustration shows how the session state on a system changes based on the status notication it receives from the remote
system. For example, if a session on a system is down and it receives a Down status notication from the remote system, the session state
on the local system changes to Init.
Figure 10. 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.
Congure BFD
This section contains the following procedures.
Congure BFD for Physical Ports
142
Bidirectional Forwarding Detection (BFD)