Symptom
BFD on main port-channel or port-channel sub-interfaces can go down after removing an unrelated Vrf/Vlan config
Conditions
Removing VRF, Vlan configuration and remove port-channel sub-interface.
Workaround
Reboot or shut / no shut of affected port channel.
Further Problem Description
Not every VLAN / VRF deletion will trigger the issue.
See Reproduciton example (bfd still up after vrf and multiple interface deletion)
N9k(config)# no vrf A
N9k(config)# no snmp-server context A vrf A
N9k(config)# router bgp 64950
N9k(config-router)# no vrf A
N9k(config-router)# no interface port-channel107.3749
N9k(config)# no interface Vlan201
N9k(config)# no interface Vlan15
# sh bfd nei vrf all
OurAddr NeighAddr LD/RD RH/RS Holdown(mult) State Int Vrf Type
10.1.1.1 10.1.1.2 1090519044/1090519044 Up N/A(3) Up Po107.3747 B SH
10.2.2.1 10.2.2.2 1090519045/1090519045 Up N/A(3) Up Po107.3752 C SH
N9k(config)# no vlan 15
-> now BFD went down on unrelated interfaces
# sh bfd nei vrf all
OurAddr NeighAddr LD/RD RH/RS Holdown(mult) State Int Vrf Type
10.1.1.1 10.1.1.2 1090519044/0 Down N/A(3) Down Po107.3747 B SH
10.2.2.1 10.2.2.2 1090519045/0 Down N/A(3) Down Po107.3752 C SH
