In a VXLAN-based campus or data center network, different node roles are defined to ensure proper traffic forwarding between traditional networks, the VXLAN overlay, and external networks. According to HCIP Datacom Campus Network documentation,edge nodes(also known as VTEPs) are responsible for encapsulating and decapsulating traffic between traditional Layer 2 or Layer 3 networks and the VXLAN overlay network. This allows legacy networks to communicate with virtualized VXLAN segments.
However, when traffic needs to leave the VXLAN fabric and accessexternal networks, such as a WAN, Internet, or another non-VXLAN domain, theborder nodeis used. The border node sits at the boundary of the VXLAN fabric and provides interconnection between the VXLAN network and external routing domains. It performs functions such as VXLAN termination, route advertisement, and traffic forwarding between overlay and underlay or external networks.
In BGP EVPN-based VXLAN deployments, the border node typically participates in BGP routing to exchange reachability information with external devices, ensuring seamless communication between VXLAN tenants and outside networks. This architectural separation improves scalability, simplifies network design, and enhances control over traffic entering or leaving the VXLAN fabric. Therefore, the correct node through which a VXLAN network accesses an external network is theBordernode.
