The default interval for BFD packets is 1 second. BFD uses Hello packets to detect the liveness and faults on a connection. BFD Hello Interval packet is sent at the default interval of 1000 milliseconds on all connections1. This command can be used to change the hello interval for a transport color. The interval for transmitting and receiving BFD packets can also be configured on the interface level or the BFD session level, depending on the device and the protocol234. The BFD detection time is calculated as the product of the local detection multiplier and the agreed remote transmission interval. The lower the BFD detection time, the faster the BFD session can detect a fault. However, a lower BFD detection time also consumes more system resources and bandwidth. Therefore, the BFD detection time should be configured according to the network situation and performance requirements. References:
: Bidirectional Forwarding Detection - Cisco
: Configuring the BFD Detection Time - CloudEngine 16800 … - Huawei