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, startup timer, and the global keepalive timers (transmit interval, minimum receive interval, detect multiplier, and echo receive interval) and the global multihop session timers 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, including Ethernet and port-channel subinterfaces.

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

Diagram

Classes

nxos

Name	Type	Constraint	Mandatory	Default Value
devices	List	devices	No
device_groups	List	device_groups	No
global	Class	global	No
templates	List	templates	No
interface_groups	List	interface_groups	No

nxos

Name	Type	Constraint	Mandatory	Default Value
devices	List	devices	No
device_groups	List	device_groups	No
global	Class	global	No
templates	List	templates	No

devices (nxos)

Name	Type	Constraint	Mandatory	Default Value
configuration	Class	configuration	No

device_groups (nxos)

Name	Type	Constraint	Mandatory	Default Value
configuration	Class	configuration	No

global (nxos)

Name	Type	Constraint	Mandatory	Default Value
configuration	Class	configuration	No

templates (nxos)

Name	Type	Constraint	Mandatory	Default Value
configuration	Class	configuration	No

interface_groups (nxos)

Name	Type	Constraint	Mandatory	Default Value
configuration	Class	configuration	No

configuration (nxos.devices)

Name	Type	Constraint	Mandatory	Default Value
interfaces	Class	interfaces	No
bfd	Class	bfd	No

configuration (nxos.interface_groups)

Name	Type	Constraint	Mandatory	Default Value
subinterfaces	List	subinterfaces	No
bfd	Class	bfd	No

interfaces (nxos.devices.configuration)

Name	Type	Constraint	Mandatory	Default Value
loopbacks	List	loopbacks	No
vlans	List	vlans	No
ethernets	List	ethernets	No
port_channels	List	port_channels	No

ethernets (nxos.devices.configuration.interfaces)

Name	Type	Constraint	Mandatory	Default Value
subinterfaces	List	subinterfaces	No
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
subinterfaces	List	subinterfaces	No
bfd	Class	bfd	No

port_channels (nxos.devices.configuration.interfaces)

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

subinterfaces (nxos.devices.configuration.interfaces.ethernets)

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	Any	String or Integer[min: 0]	No
hardware_offload	Boolean	true, false	No
slow_timer	Integer	min: 1000, max: 30000	No
startup_timer	Integer	min: 0, max: 60	No
interval	Integer	min: 10, max: 999	No
min_rx	Integer	min: 10, max: 999	No
multiplier	Integer	min: 1, max: 50	No
echo_rx_interval	Integer	min: 0, max: 999	No
multihop_interval	Integer	min: 250, max: 999	No
multihop_min_rx	Integer	min: 250, max: 999	No
multihop_multiplier	Integer	min: 1, max: 50	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	Any	String or Integer[min: 0]	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	IP		No
vpc_watch	Boolean	true, false	No
track_member_link	Boolean	true, false	No
authentication_type	Choice	none, keyed-sha1, meticulous-keyed-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: Global BFD keepalive timers

nxos:
  devices:
    - name: LEAF1
      configuration:
        feature:
          bfd: true
        bfd:
          interval: 100
          min_rx: 100
          multiplier: 5
          echo_rx_interval: 100
          slow_timer: 2000
          startup_timer: 10

Example 3: Global BFD multihop session timers

nxos:
  devices:
    - name: BORDER-LEAF1
      configuration:
        feature:
          bfd: true
        bfd:
          multihop_interval: 300
          multihop_min_rx: 300
          multihop_multiplier: 3

Example 4: 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
              areas:
                - id: 0.0.0.0
        interfaces:
          ethernets:
            - id: 1/1
              description: "FABRIC: SPINE1 Eth1/1"
              mtu: 9216
              ospf:
                process: "1"
                area: 0.0.0.0
                network: point-to-point
              bfd:
                interval: 50
                min_rx: 50
                multiplier: 3
                echo: false

Example 5: 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: keyed-sha1
                authentication_key_id: 1
                authentication_key: BFD-SECRET

Example 6: 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

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