Arista goes big with campus wireless tech

Arista Networks is making moves in campus mobility, announcing architectural updates designed to help enterprises build large-scale wireless networks.

Arista’s new Virtual Ethernet Segment with Proxy ARP (VESPA) for WLAN mobility will let enterprise customers design massive Wi-Fi roaming domain networks with more than 500,000 multivendor clients and 30,000 Arista wireless access points.

VESPA is part of Arista’s Cognitive Campus/Cognitive Wi-Fi package, which is based on the cloud-based wireless technology it bought from Mojo Networks in 2018. That technology bypasses the traditional on-premises Wi-Fi controller to manage APs and lets the wireless control and management plane run in the cloud, offering scalability and flexibility, according to Sriram Venkiteswaran, Arista’s director of product management. It also provides the ability to run unified wired and wireless network management, in this case via Arista’s CloudVision management package, Venkiteswaran said.

Arista VESPA uses data center-style technologies solve two big Wi-Fi problems, Venkiteswaran said. The first is scale. With a network for a large university, or a large campus with multiple buildings, “one of the biggest challenges with the legacy architecture is that there is no concept of a seamless, roaming domain across the entire campus,” he said. “So the current architecture would require the network to be broken down to multiple mobility domains because of how it’s architected, with the limitations of traditional controller-based wireless architecture.” 

The second problem is resiliency. “When you deploy these wireless clients and controllers, you have this concept of failover, and when there is a failover, it takes an order of minutes, or you have an outage. And for customers that are running mission-critical or business-critical applications, any downtime can be massively disrupting,” Venkiteswaran said.

With VESPA, Arista has applied high-scale, data-center principles like Virtual Extensible LAN (VXLAN) and Ethernet VPN (EVPN) to wireless campus networks to enable a single, massive roaming domain supporting over 500,000 clients with high resiliency and fast failover, Venkiteswaran said. The system also supports zero-touch provisioning that lets customers rapidly activate and configure access points after connecting to the cloud.

In a white paper describing how VESPA works, Arista wrote:

The first component of VESPA involves Arista access points creating VXLAN tunnels to Arista switches serving as WLAN Gateways…. Second, as device packets arrive via the AP, it dynamically creates an Ethernet Segment Identifier (Type 6 ESI) based on the AP’s VTEP IP address. These dynamically created tunnels can scale to 30K ESI’s spread across paired switches in the cluster which provide active/active load sharing (performance+HA) to the APs. Third, the gateway switches use Type 2 EVPN NLRI (Network Layer Reachability Information) to learn and exchange end point MAC addresses across the cluster. … With this architecture, adding more EVPN WLAN gateways scales both AP and user connections, to tens of thousands of end points.

To manage the forwarding information for hundreds of thousands of clients (e.g: FIB next hop and rewrite) would prove very complex and expensive if using conventional networking solutions. Arista’s innovation is to distribute this function across the WiFi access points with a unique MAC Rewrite Offload feature (MRO). With MRO, the access point is responsible for servicing mobile client ARP requests (using its own mac address), building a localized MAC-IP binding table, and forwarding client IP addresses to the WLAN gateways with the APs MAC address. The WLAN Gateways therefore only learns one (MAC) address for all the clients associated with the AP. This improves the gateway’s scaling from 10X to 100X, allowing these cost effective gateways to support hundreds of thousands of clients attached to the APs.

AVA system gets a boost

In addition to the new wireless technology, Arista is also bolstering the capabilities of its natural-language, generative AI-based Autonomous Virtual Assist (AVA) system for delivering network insights and AIOps. 

AVA is aimed at providing an intelligent assistant that’s not there to replace people but rather help them do their job better, said Jeff Raymond, vice president, EOS product management and services at Arista. 

“AVA is a chat interface into our data lake. But instead of just providing you easy search responses, like, ‘tell me where this user is sitting,’ the chat interface uses an LLM on the back end to rationalize and reason with the telemetry information and get the end user to something that’s much more precise in terms of troubleshooting, in terms of being able to just find an issue more quickly, or be able to even prevent an issue,” Raymond said. The LLM component is new and has been in product preview until now. 

With the AVA insights component, “we’re looking at being able to use our best practices, our technical expertise, but codified,” he said. Then we’re able “to run those as agents, so that we can look for problems in a network and be able to proactively alert a user before they happen.”

Arista has also added the ability to handle multi-domain event correlation across wired, wireless, data center, and security to isolate a root cause of a problem. AVA can then perform continuous monitoring and automated root cause analysis for proactive issue identification, Raymond said. 

AVA will also add support for new agents and components in the network – such as VESPA and for the VeloCloud SD/WAN technology the company recently purchased from Broadcom, Raymond said.

Ruggedized switches on tap

Lastly, Arista rolled out it first ruggedized switches targeting industrial networking edge applications. The switches include a 20-port DIN Rail switch used in industrial control panels and a 1RU 24-port switch. They support multi-gigabit ports and high-power PoE (90W). Both are engineered for harsh industrial conditions and can tolerate extreme temperatures, vibrations, shocks, and more demanding physical conditions than standard enterprise switches, Arista stated.

VESPA and the ruggedized switches are expected to be available by the first quarter of 2026.