TECHNICAL FIELD

Embodiments presented in this disclosure generally relate to network communication and, more specifically, to improved techniques for routing traffic across different virtual local area networks (VLANs) within a single bridge domain.

BACKGROUND

In a Multiprotocol Label Switching (MPLS) Ethernet virtual private network (EVPN), data centers are interconnected by means of an MPLS provider core network. Each data center may include devices that use the Multiprotocol-Border Gateway Protocol (MP-BGP) to dynamically communicate with each other. MP-BGP is a control plane based protocol that provides endpoint peer discovery and end-host reachability information distribution for overlay networks. An EVPN includes customer edge (CE) devices that are connected to provider edge (PE) devices, which form the edge of the MPLS infrastructure. A CE device can be a host, a router, a switch, etc. The PE devices provide Layer 2 virtual bridge connectivity between the CE devices. The PE devices participating in the EVPN instances can use the MP-BGP protocol to learn customer media access control (MAC) routes in the control plane.

An EVPN can support a single homing mode or a multi-homing mode. In a single homing mode, a CE device is connected to a single PE device. In a multi-homing mode, a CE device can be connected to multiple PE devices to provide redundant connectivity. For example, in EVPN multi-homed scenarios, a redundant PE device can maintain EVPN service and traffic forwarding in the event of network failures (e.g., PE device to CE device link failures, PE device failure, MPLS-reachability failure, etc.).

EVPN may also support integrated routing and bridging (IRB) deployments with multi-homing. For example, EVPN IRB enables Layer 3 forwarding among hosts across different internet protocol (IP) subnets, while maintaining the multi-homing capabilities of EVPN. In addition, EVPN IRB allows for EVPN hosts or subnets to communicate with IP VPNs. Given the increased use of EVPN-based multi-homing techniques, there has been a focus on providing further optimizations in terms of scalability, management, and security for EVPN-based multi-homing deployments.

