The bfd command in the system view enables BFD globally and accesses the BFD global view.
The undo bfd command disables BFD globally.
By default, BFD is disabled.
You must enable BFD before performing BFD-related configurations.
If the Layer-2 interfaces of the two devices are connected through a Layer-2 switch that provides the BFD function, and multicast IP addresses are used to set up BFD sessions, when the global BFD function is enabled on the switch, run the default-ip-address command to configure different default multicast IP addresses for the two devices and switch. Otherwise, the switch cannot forward the BFD multicast packets, resulting in BFD session interruption.