User's Manual

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556
Users Manual of CS-6306R
If min_rx_interval on the local end is decreased, the local detection time cannot be modified until the packets
reset by the peers F field are received, which ensures that the transmission interval of BFD control packets
on the peer has been decreased before the decrease of local detection time. However, if min_tx_interval is
decreased, the local transmission interval of BFD control packets may decrease immediately; if
min_rx_interval is increased, the local detection time will increase immediately.
55.2.2 Activating the Port BFD Query Mode
The port BFD query mode is not activated by default.
In query mode, we suppose that each system has an independent method to confirm its connection with other
systems. Once a BFD session is established, the system stops transmitting BFD control packets unless a
certain system requires explicit connectivity checkup. In a system where explicit connectivity checkup is
required, the system transmits short-sequence BDF control packets and claims the session is down if it
doesn't receive the response packets in the checkup period. If the response packets are received from the
peer in the checkup period, it means the forwarding path is normal and the BFD control packets then stop
being transmitted.
Run the following command to achieve the previous purpose:
Command Purpose
bfd demand enable Activates the BFD query mode.
The system supports to activate or deactivate the BFD query mode.
55.2.3 Activating Port BFD Echo
Port BFD echo is not activated by default.
After the BFD echo is activated, if the neighbor supporting BFD echo is up, the control packets are transmitted
according to the interval configured by slow-timers. The connectivity detection is finished by the echo packets
and the transmission interval of echo packets is the time configured by min_echo_rx_interval.
Run the following command to achieve the previous purpose:
Command Purpose
bfd echo enable<cr>|<number>
Activates BFD echo.
The activation and shutdown of echo functionality on an already “up” neighbor has no impact on this
neighbor’s status, but the transmission interval of control packets is affected.