Seamless VXLAN Stitching with Symmetric EVPN Type 2 Routes using Data Center Interconnect

Data Center Interconnect (DCI) enables you to segment the DC fabric into multiple points of delivery (PODs). Seamless stitching of Virtual Extensible LAN (VXLAN) Virtual Network Identifiers (VNIs) allows you to selectively stretch your Layer 2 network between PODs. Each POD will follow a spine and leaf design. The leaf nodes in a given POD will only establish VXLAN tunnels with leaves and spines in their POD. Spines will transport traffic to other spines of different PODs. VXLAN stitching with DCI is ideal for larger networks since it reduces MAC flooding by reducing the required number of VXLAN tunnels between PODs.

Symmetric integrated routing and bridging (IRB) in an EVPN-VXLAN environment occurs when the ingress and egress VXLAN tunnel end points (VTEPs) perform both routing and bridging on each side of the VXLAN tunnel. The ingress provider edge (PE) device performs a MAC lookup followed by an IP lookup, and the egress PE performs the opposite, an IP lookup followed by a MAC lookup.