RFC 7432 (BGP MPLS-Based Ethernet VPN) specifies multiprotocol extensions to BGP to exchange Layer 2 routes in an MPLS Ethernet VPN network. These extensions are useful in DCI scenarios.
A BGP EVPN-based IP Fabric consists of BGP EVPN for VxLAN overlay networks and a broad set of Layer 2, Layer 3, and infrastructure features to enable seamless deployment, on-demand usage of forwarding entries in hardware, and minimization of flooding in the network.
The following figure shows a supported topology where the SLX devices are nodes in a BGP EVPN spine in an IP Fabrics network.
The leaf nodes in the IP Fabric can be any of the supported hardware platforms. A BGP EVPN-based Multi-Chassis Trunk (MCT) solution is also supported on those platforms. However, using a co-located BGP EVPN spine and a BGP EVPN MCT on the same switch is not supported. For a list of supported platforms, see Supported Hardware.
VxLANs provide the inter-connectivity between leaf nodes in an IP Fabric network. VxLAN tunnels are established between leaf nodes. The following figure illustrates this VxLAN connectivity.
Note
Leaf nodes will be dual-homed.