Open, Unified Datacenter Networking with VMware and Cisco

Sabina Anja of VMware by Broadcom and Lukas Krattiger of Cisco presented a joint architecture integrating VCF Networking with Cisco Nexus fabrics. The session covered VMM integration support with ACI, VXLAN EVPN interoperability between the VCF distributed transit gateway and Cisco ACI and NX-OS, the VCF route controller, tunnel stitching at the fabric, and plans for fully distributed tunnel termination. The session at Networking Field Day 41 was billed as the first joint Cisco and VMware presentation in roughly ten years.

Anja and Krattiger confirmed that both companies support ACI VMM integration, though Krattiger stressed it was never mandatory and urged a routed EVPN approach over VLAN coordination. Cisco opened ACI’s edge with a border gateway that speaks VXLAN EVPN, bringing ACI and NX-OS under the Cisco Nexus One umbrella. On the VCF side, a route controller acts as a directory of every VM and its IP address, comparable to a route reflector but not one, and runs active-standby to avoid a single point of failure. The distributed transit gateway runs an EVPN engine in the ESX kernel and advertises each VM as a /32 type 5 route with the hosting ESX server’s VTEP as next hop, giving the fabric exact location rather than a summary. A vMotion triggers an updated advertisement. Today, VXLAN tunnels terminate at a centralized point such as a spine, where Cisco’s border gateway function re-encapsulates traffic. Krattiger said he got the integration working within hours because the required EVPN functions already existed.

The presenters argued that native stitching ends the decapsulate-and-reencapsulate handoff between overlays and gives network engineers clear visibility and a policy point at the interconnect. Anja framed the benefit operationally: instead of tracing MAC addresses hop by hop and waiting on virtualization teams, engineers can run show ip route to find exactly where a workload lives, which matters as AI workloads make traffic heavier and fabrics larger. Francois Tallet added that modes are chosen per transit gateway, so centralized BGP, distributed VLAN, and EVPN gateways can coexist for one tenant. The next step, roughly a year out, terminates tunnels directly at the leaf switch, eliminating centralized gateways entirely.