Operation Manual – BFD-GR
H3C S3610&S5510 Series Ethernet Switches
Chapter 1 BFD Configuration
1-4
Figure 1-1
BFD control packet format
z
Vers: Protocol version. The protocol version is 1.
z
Diag: This bit indicates the reason for the last transition of the local protocol from
up
to some other state.
lists the states.
Table 1-1
Diag bit values
Diag
Description
0 No
Diagnostic
1
Control Detection Time Expired
2
Echo Function Failed
3
Neighbor Signaled Session Down
4
Forwarding Pane Reset
5 Path
Down
6
Concatenated Path Down
7 Administratively
Down
8~31
Reserved for future use
z
State (Sta): Current BFD session state. Its value can be 0 for AdminDown, 1 for
Down, 2 for Init, and 3 for Up.
z
Demand (D): If set to 1, it means the transmitting protocol wishes to operate in the
query mode; if set to 0, it means the transmitting protocol ignores the query mode
or cannot operate in the query mode.
z
Poll (P): If it is set to 1, the transmitting protocol requests the connection
acknowledgement or acknowledges a parameter change. If it is set to 0, the
transmitting protocol does not request the acknowledgement.
z
Final (F): If it is set to 1, the transmitting protocol responds to a received BFD
control packet that has the Poll (P) bit set. If it is set to 0, the transmitting protocol
does not respond to any received BFD control packet that has the Poll (P) bit set.
