3com S7906E Instruccion De Instalación

 

1-4 

z 

At present, only the asynchronous mode is supported.  

z 

When a BFD session operates in Echo mode, the session is independent of the operating mode.  

z 

When the connectivity to another system needs to be verified explicitly, a system sends several 

BFD control packets that have the Poll (P) bit set at the negotiated transmit interval. If no response 

is received within the detection interval, the session is considered down. If the connectivity is found 

to be up, no more BFD control packets are sent until the next command is issued. 

 

After a BFD session is established, both ends can negotiate the related BFD parameters, such as the 

minimum transmit interval, minimum receive interval, initialization mode, and packet authentication 

mode. After that, both ends use the negotiated parameters, without affecting the current session state.  

 illustrates the BFD control packet format. BFD control packets are encapsulated into UDP 

packets with port number 3784.  

Figure 1-3 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 

 lists the states.  

Table 1-1 Diag bit values 

0 No 

Diagnostic 

1 

Control Detection Time Expired 

2 

Echo Function Failed 

3 

Neighbor Signaled Session Down 

4 

Forwarding Plane Reset 

5 Path 

Down 

6 

Concatenated Path Down