Fabric Forwarding

Fabric forwarding configuration manages VXLAN fabric-level forwarding settings on NX-OS devices, including the anycast gateway MAC address used for distributed default gateway across all VTEP leaf switches, the administrative distance for fabric routes, per-VLAN MAC address limits, selective host probe for optimizing ARP suppression, and duplicate host IP address detection and recovery in VXLAN EVPN deployments. The anycast gateway MAC is a critical setting that must be consistent across all leaf switches in a VXLAN fabric to enable seamless host mobility and distributed routing.

Fabric forwarding configuration manages VXLAN fabric-level forwarding settings on NX-OS devices, including the anycast gateway MAC address used for distributed default gateway across all VTEP leaf switches, the administrative distance for fabric routes, per-VLAN MAC address limits, and selective host probe for optimizing ARP suppression in VXLAN EVPN deployments. The anycast gateway MAC is a critical setting that must be consistent across all leaf switches in a VXLAN fabric to enable seamless host mobility and distributed routing.

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

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

configuration (nxos.devices)

Name	Type	Constraint	Mandatory	Default Value
fabric_forwarding	Class	fabric_forwarding	No

fabric_forwarding (nxos.devices.configuration)

Name	Type	Constraint	Mandatory	Default Value
anycast_gateway_mac	MAC		No
distance	Integer	min: 1, max: 255	No
dup_host_ip_addr_detection_moves	Integer	min: 1, max: 1000	No
dup_host_ip_addr_detection_seconds	Integer	min: 2, max: 36000	No
dup_host_recovery_timer_timeout	Integer	min: 30, max: 36000	No
dup_host_recovery_timer_recover_count	Integer	min: 1, max: 3000	No
limit_vlan_mac	Integer	min: 5, max: 4096	No
selective_host_probe	Boolean	true, false	No

fabric_forwarding (nxos.devices.configuration)

Name	Type	Constraint	Mandatory	Default Value
anycast_gateway_mac	MAC		No
distance	Integer	min: 1, max: 255	No
limit_vlan_mac	Integer	min: 5, max: 4096	No
selective_host_probe	Boolean	true, false	No

Examples

Example 1: VXLAN leaf with anycast gateway MAC and selective host probe

nxos:
  devices:
    - name: LEAF1
      configuration:
        fabric_forwarding:
          anycast_gateway_mac: 20:20:00:00:10:12
          selective_host_probe: true

Example 2: VXLAN leaf with anycast gateway MAC and custom VLAN MAC limit

nxos:
  devices:
    - name: LEAF2
      configuration:
        fabric_forwarding:
          anycast_gateway_mac: 20:20:00:00:10:12
          limit_vlan_mac: 1024
          selective_host_probe: true

Example 3: Border leaf with anycast gateway MAC and fabric route distance

nxos:
  devices:
    - name: BORDER-LEAF1
      configuration:
        fabric_forwarding:
          anycast_gateway_mac: 20:20:00:00:10:12
          distance: 200
          selective_host_probe: true

Example 4: VXLAN leaf with tuned duplicate host IP address detection and recovery

nxos:
  devices:
    - name: LEAF3
      configuration:
        fabric_forwarding:
          anycast_gateway_mac: 20:20:00:00:10:12
          dup_host_ip_addr_detection_moves: 10
          dup_host_ip_addr_detection_seconds: 300
          dup_host_recovery_timer_timeout: 60
          dup_host_recovery_timer_recover_count: 10

Examples

Example 1: VXLAN leaf with anycast gateway MAC and selective host probe

nxos:
  devices:
    - name: LEAF1
      configuration:
        fabric_forwarding:
          anycast_gateway_mac: 20:20:00:00:10:12
          selective_host_probe: true

Example 2: VXLAN leaf with anycast gateway MAC and custom VLAN MAC limit

nxos:
  devices:
    - name: LEAF2
      configuration:
        fabric_forwarding:
          anycast_gateway_mac: 20:20:00:00:10:12
          limit_vlan_mac: 1024
          selective_host_probe: true

Example 3: Border leaf with anycast gateway MAC and fabric route distance

nxos:
  devices:
    - name: BORDER-LEAF1
      configuration:
        fabric_forwarding:
          anycast_gateway_mac: 20:20:00:00:10:12
          distance: 200
          selective_host_probe: true