In modern enterprise campus environments, most application traffic flows between wired and wireless users and between resources that are hosted within on-premises data centers or across cloud. Network administrators build structured IP addressing plans with VLAN and subnet on a per-distribution block and enable segmentation through routed overlay or selectively stretching flood-free IP subnets with Distributed Anycast Gateway Routed VXLAN fabric network.

With the digitally evolving IP-everywhere networks, in some scenarios network administrators are mandated to maintain modern fabric networks, while supporting scarce VLAN segments with legacy enterprise network applications and endpoints operating at link-layer without IP addresses. The Distributed Anycast Gateway (DAG) technology supports classic methods to extend the Layer 2 flood-boundary for selective VLANs over the dynamic Layer 2 VXLAN tunnels.

The DAG-bridged overlay networks stretch IP subnets and the Layer 2 VLAN flood-boundary with traditional Integrated Routing and Bridging (IRB) function between targeted Cisco Catalyst 9000 series switches implemented in EVPN multihoming fabric mode. The DAG-bridged overlay networks extend the Layer 2 flood boundary across fabric networks for all endpoints including hosts with and without IP addresses.

Cisco Catalyst 9000 series switches support the coexistence of routed, DAG-routed and DAG-bridged overlay networks that provide the flexibility to scale fabric networks while enabling enterprise application requirements.