BFD

BFD (Bidirectional Forwarding Detection) provides sub-second failure detection for routing protocols and static routes on NX-OS devices. Global BFD settings configure the echo interface, hardware offload, slow timer, and startup timer under the bfd section. Interface-level BFD settings configure session parameters including transmit/receive intervals, detect multiplier, echo mode, authentication, and port-channel-specific options like per-link and track-member-link under each interface type’s bfd sub-section.

Diagram

Classes

configuration (nxos.devices)

Name	Type	Constraint	Mandatory	Default Value
bfd	Class	[bfd]	No

loopbacks (nxos.devices.configuration.interfaces)

Name	Type	Constraint	Mandatory	Default Value
bfd	Class	[bfd]	No

vlans (nxos.devices.configuration.interfaces)

Name	Type	Constraint	Mandatory	Default Value
bfd	Class	[bfd]	No

ethernets (nxos.devices.configuration.interfaces)

Name	Type	Constraint	Mandatory	Default Value
bfd	Class	[bfd]	No

port_channels (nxos.devices.configuration.interfaces)

Name	Type	Constraint	Mandatory	Default Value
bfd	Class	[bfd]	No

bfd (nxos.devices.configuration)

Name	Type	Constraint	Mandatory	Default Value
echo_interface_type	Choice	ethernet, loopback, mgmt, port-channel, vlan, vni	No
echo_interface_id	String		No
hardware_offload	Boolean	true, false	No
slow_timer	Integer	min: 1000, max: 30000	No
startup_timer	Integer	min: 0, max: 60	No

bfd (nxos.devices.configuration.interfaces.loopbacks)

Name	Type	Constraint	Mandatory	Default Value
interval	Integer	min: 0, max: 999	No
min_rx	Integer	min: 0, max: 999	No
multiplier	Integer	min: 0, max: 50	No
echo	Boolean	true, false	No
echo_rx_interval	Integer	min: 0, max: 999	No
optimize_subinterface	Boolean	true, false	No
per_link	Boolean	true, false	No
source_ip	String		No
vpc_watch	Boolean	true, false	No
track_member_link	Boolean	true, false	No
authentication_type	Choice	none, sha1, met-sha1	No
authentication_key_id	Integer	min: 1, max: 255	No
authentication_key	String		No
authentication_interop	Boolean	true, false	No

Examples

Example 1: Global BFD with echo interface and hardware offload

nxos:
  devices:
    - name: LEAF1
      configuration:
        feature:
          bfd: true
        bfd:
          echo_interface_type: loopback
          echo_interface_id: "0"
          hardware_offload: true
          slow_timer: 2000

Example 2: BFD timers on fabric uplinks with OSPF

nxos:
  devices:
    - name: LEAF1
      configuration:
        feature:
          bfd: true
          ospf: true
        bfd:
          echo_interface_type: loopback
          echo_interface_id: "0"
        routing:
          ospf_processes:
            - name: "1"
              bfd: true
        interfaces:
          ethernets:
            - id: 1/1
              description: "FABRIC: SPINE1 Eth1/1"
              mtu: 9216
              ospf:
                process: "1"
                area: 0.0.0.0
                network: p2p
              bfd:
                interval: 50
                min_rx: 50
                multiplier: 3
                echo: false

Example 3: BFD with SHA-1 authentication on SVI interfaces

nxos:
  devices:
    - name: LEAF1
      configuration:
        feature:
          bfd: true
          interface_vlan: true
        bfd:
          echo_interface_type: loopback
          echo_interface_id: "0"
        interfaces:
          vlans:
            - id: 100
              vrf: PROD
              bfd:
                interval: 100
                min_rx: 100
                multiplier: 5
                authentication_type: sha1
                authentication_key_id: 1
                authentication_key: BFD-SECRET

Example 4: BFD per-link on port-channel with vPC watch

nxos:
  devices:
    - name: LEAF1
      configuration:
        feature:
          bfd: true
        interfaces:
          port_channels:
            - id: 1
              description: "VPC: PEER-LINK"
              bfd:
                interval: 50
                min_rx: 50
                multiplier: 3
                per_link: true
                vpc_watch: true
                track_member_link: true