What is stacking and how does it differ from clustering?

Stacking and clustering are two approaches to managing multiple switches as one, but they work very differently.

Stacking

• Multiple switches physically connected with dedicated stacking cables
• Appear as single switch — one management IP, one config
• Shared switching fabric between members
• Cross-stack LACP, ports treated as one device
• Typically 4-9 members per stack

Clustering

• Switches remain independent, connected via regular ethernet
• Managed through a master switch or NMS
• Each device keeps own config, but managed collectively
• Larger scale (dozens to hundreds of devices)

Comparison Table

Stacking Topologies

• Ring: Each switch connects to two others (best redundancy)
• Chain: Daisy-chain (single point of failure)

Failover

• Master election on failure (automatic)
• Stack member failure isolated; traffic reroutes around
• Firmware updates typically require reboot of all members

When to Use What

• Stack: Single-cabinet access, high density needed, unified management
• Cluster: Distributed sites, campus deployments, larger scale

Considerations

• Stacking cables and modules add cost
• Version mismatch can prevent stack formation
• Recovery from split-brain requires care