When it comes to building campus networks, there is a religion around stacking versus chassis-based systems.
In my network engineer days, I lived on both sides of that holy war. Initially, it was chassis or nothing, but I worked for a big financial firm with large budgets and didn’t give much credence to other options. As time went on, I began to appreciate a stack’s flexibility and budget flexibility, as one could start with a small network stack and add to it when required.
However, neither solution is perfect. Stacking, developed decades ago, hasn’t evolved much. One of the big benefits of a stack is that it simplifies switch management by treating multiple devices as a single entity. However, these solutions rely on proprietary tools and protocols, limit flexibility with fixed topologies like rings or chains, and can often lock a company into a specific vendor.
The network has continued to grow in importance but has also grown more complex. A recent ZK Research/Cube Research study found that 93% of organizations believe the network is more critical to business operations than two years ago, but in that same time frame, 80% believe the network has become more complex. Given the network’s role, where it connects everything in a company, simplicity must be part of the innovation cycle in modernized network infrastructure.
This week, Arista Networks Inc., best known for its high-performance networks, announced new features that bring the benefits of stacking without the associated problems. Its latest “SWitch Aggregation Group,” or SWAG, is a feature in EOS that allows multiple Arista switches to be managed with one IP address and from a single command-line or CLI interface.
The second one is leaf-spine stack or LSS management, a feature in Arista’s CloudVision platform that organizes and collectively manages switches, regardless of their physical arrangement. These capabilities address issues such as conserving IP address pools, a growing concern for organizations managing large, distributed networks.
“We are modernizing stacking by solving the problem to benefit customers so that they can get more IP address space efficiency localization on campus — not just with managing a problem they have, conserving IP addresses, but, more importantly, helping them with another major challenge, reducing their total cost of ownership on tools,” said Kumar Srikantan, vice president and general manager of Zero Trust campus networking at Arista.
Organizations usually stick to familiar workflows and tools rather than adopt entirely new approaches, even if they are open to transitioning over time. To address this, Srikantan said Arista provides stacking to replicate the behavior of legacy systems, allowing customers to “lift and shift” their existing setups while gradually migrating to modern architectures.
Arista’s approach extends the widely used leaf-spine architecture to campus networks. Customers already using Arista’s technology in data centers can more easily transition to campus networks. SWAG supports standard ethernet cabling, diverse topologies, and modern designs like leaf-spine. Customers can manage up to 40 switches in a cluster, eliminating the need for proprietary cables and making the system more adaptable to different network setups. Leaf-spine architectures have seen rapid adoption in data centers, as they require scaling up quickly and cost-effectively with minimal disruption. Campus networks are seen as more endpoints connected because of mobility and IoT and have the same requirements.
“We have this feature called smart system upgrade, which operates on an individual switch level,”s aid Sriram Venkiteswaran, director of product management at Arista. “But now, with LSS management, customers can organize the switches however they want.”
SWAG and LSS management expand on multi-chassis link aggregation groups or MLAG capabilities to meet different customer needs. Though MLAG provides redundancy and load balancing across switches, it doesn’t offer single IP address management or a unified CLI, which some customers prefer for simplicity. SWAG fills this gap by grouping switches into a single cluster with one IP address and CLI, making it easier to manage distributed networks and transition from legacy stacking systems.
CloudVision LSS complements SWAG by decoupling the management layer from the physical network architecture. It allows switches to be logically grouped and managed across different physical setups, whether leaf-spine or traditional stacking. It also provides advanced management features like telemetry, provisioning, and artificial intelligence-driven insights.
“When we launch, we don’t expect customers to move away from MLAG to a SWAG model,” Venkiteswaran concluded. “I think SWAG will see more adoption with customers migrating away from an existing legacy competitive solution that uses stacking or similar setups. That’s where we would see most of our SWAG deployments.”
Though the campus network arena is crowded, Arista offers compatibility between legacy and modern systems, enabling customers to migrate gracefully from one generation to another. Its mission of providing a single operating system across all its products has made it a de facto standard in high-performance computing, cloud, and data centers, and it’s now targeting the campus in a bigger way.
Together, SWAG and LSS simplify operations, while MLAG remains a strong option for those who don’t need single-IP management but want robust network performance. These technologies give customers the flexibility to choose what fits their needs.
