Helper Router Configuration

The Helper router is enabled under VRRP per VRID per VLAN interface on access SPB switches that ingress to customer VLANs. Helper router route tables confine routes to connected VLAN interfaces where an interface represents a customer VLAN. The Helper router learns the identity of Main routers by the propagation of type 250 TLV through the SPB network by IS-IS. Helper routers redirect unresolved destination networks to the Main routers.

The Main router responds to ARP requests for any virtual IP address and sends VRRP advertisements to ensure the virtual MAC remains in bridge FDBs within the SPB domain. Helper routers install the VRRP virtual MAC address into the local filter database for packet processing by the forwarding plane.

Use the vrrp fabric-route-mode command in interface configuration mode, specifying the VRID and the helper-router option, to enable this SPB node as a Helper router.