bfd echo-src-ip-address 3.3.3.3
vlan 1
name "DEFAULT_VLAN"
no untagged A1
untagged A2-A24
ip address dhcp-bootp
exit
vlan 10
name "VLAN10"
untagged A1
bfd min-echo-receive-interval 700
ip address 172.16.4.2 255.255.255.0
ip ospf 172.16.4.2 area backbone
ip ospf 172.16.4.2 bfd
exit
no allow-v2-modules
Switch(config)#
show bfd
Bidirectional Forwarding Detection (BFD) Information
Administrative Status : Enabled
Echo Source IP : 3.3.3.3
Maximum number of sessions supported : 128
Number of sessions reserved for internal use : 0
Total Number of Sessions : 1
Number of Sessions Up : 1
Number of Sessions Down : 0
Global Statistics:
Total Number of Control Packets Transmitted : 8980
Total Number of Control Packets Received : 8974
Total Number of Control Packets Dropped : 0
Session VLAN Source IP Destination IP Echo State Application
-------- ------ ---------------- ---------------- ---------- ----------- -----------
1 10 172.16.4.2 172.16.4.1 Enabled Up OSPF/STATIC
Switch(config)#
Note with respect to the previous example:
• If BFD configuration is removed on SWITCH-1 on vlan-10 on EITHER OSPF or STATIC, still the BFD session
is maintained as UP on SWITCH2 with OSPF/STATIC applications. SWITCH1 maintains the session only with
BFD enabled application in this case.
• If OSPF or STATIC Configuration itself is removed on SWITCH-1 on vlan-10, still the BFD session is
maintained as UP on SWITCH2 with OSPF/STATIC applications. SWITCH1 maintains the session only with
configured application in this case.
• If BFD configuration is removed on SWITCH-1 on vlan-10 on BOTH OSPF and STATIC, the BFD session will
go DOWN on SWITCH2 with OSPF/STATIC applications. SWITCH1 does not maintain any session.
• If OSPF and STATIC Configuration are removed on SWITCH-1 on vlan-10, the BFD session is maintained as
DOWN on SWITCH2 with STATIC applications. SWITCH1 does not maintain any session.
• If OSPF adjacency breaks due to any reason (for example change in OSPF authentication etc) on SWITCH-1,
BFD session will be maintained in UP state since STATIC is also registered on it.
Chapter 18 Bidirectional Forwarding Detection (BFD)
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