Stackable Switch - Functionality

Functionality

Features associated with stackable switches can include:

• Single IP address for multiple units. Multiple switches can share one IP address for administrative purposes, thus conserving IP addresses.
• Single management view from multiple interfaces. Stack-level views and commands can be provided from a single Command Line Interface (CLI) and/or embedded Web interface. The SNMP view into the stack can be unified.
• Stacking resiliency. Multiple switches can have ways to bypass a “down” switch in a stack, thus allowing the remaining units to function as a stack even with a failed or removed unit.
• Layer 3 redundancy. Some stackable architectures allow for continued Layer 3 routing if there is a “down” switch in a stack. If routing is centralized in one unit in the stack, and that unit fails, then there must be a recovery mechanism to move routing to a backup unit in the stack.
• Mix and match of technology. Some stackable architectures allow for mixing switches of different technologies or from different product families, yet still achieve unified management. For example, some stacking allows for the mixing 10/100 and Gigabit switches in a stack.
• Dedicated stacking bandwidth. Some switches come with built-in ports dedicated for stacking, which can preserve other ports for data network connections and can avoid the possible expense of an additional module to add stacking. Proprietary data handling or cables can be used to achieve higher bandwidths than standard Gigabit or 10-Gigabit connections.
• Link aggregation of ports on different units in the stack. Some stacking technologies allow for link aggregation from ports on different stacked switches either to other switches not in the stack (for example a core network) or to allow servers and other devices to have multiple connections to the stack for improved redundancy and throughput. Not all stackable switches support link aggregation across the stack.

There is not universal agreement as to the threshold for being a stackable versus being a standalone switch. Some companies call their switches stackable if they support a single IP address for multiple units even if they lack other features from this list. Some industry analysts have said a product is not a stackable if it lacks one of the above features (e.g., dedicated bandwidth).