Bidirectional Forwarding Detection (BFD) Notes
Bidirectional Forwarding Detection (BFD)
– It can check the connection status between two layer 3 devices in the periods of milliseconds and inform the upper layer routing protocol to take action
– Supported protocols
-> OSPF
-> IS-IS
-> EIGRP
-> BGP
Configuration
– Keepalive parameters
-> Sending / receiving frequency
-> Multiplier
– Associating it with routing protocols
int s0/0
bfd interval <ms> min-rc <ms> multiplier <number>
EIGRP
router eigrp 1
bfd { interface <int> | all-interfaces }
OSPF
router ospf 1
bfd all-interfaces
– or –
int s0/0
ip ospf bfd [disabled]
IS-IS
router isis ABC
bdf all-interfaces
– or –
int s0/0
isis bfd [disable]
BGP
router bgp 100
neighbor <ip add> fall-over bfd
sh bfd neighbors
sh bfd neighbors detail
BFD only works if both sides are configured