Cisco Systems Cisco Systems Cisco Systems Cisco Systems Nokia EVPN Integrated Routing and Bridging (IRB) fabrics provide a flexible and extensible method for Layer-2 and Layer-3 overlay network connectivity. [EVPN-IRB] defines operation for symmetric and asymmetric EVPN IRB using distributed anycast gateway architecture (DAG). In a DAG architecture, both bridging and first-hop routing functions for overlay subnets are located on leaf PEs, with first-hop routing provided by a distributed anycast gateway provisioned across the leaf PEs. This document describes an architecture and operation for EVPN Centralized Anycast Gateway (CAG), which allows the first- hop routing function for overlay subnets to be centralized on designated IRB GWs while the bridging function is still located on the leaf PEs. The documents also covers trade-offs of deploying a CAG as compared with DAG. It further describes operation for inter- op between CAG and DAG based EVPN-IRB network overlays.