Datasheet

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The active switch automatically elects a standby switch within the stack. The active switch creates and updates all
the switching/routing/wireless information and constantly synchronizes that information with the standby switch. If
the active switch fails, the standby switch assumes the role of the active switch and continues to the keep the stack
operational. Access points continue to remain connected during an active-to-standby switchover.
A working stack can accept new members or delete old ones without service interruption. StackWise-480 creates a
highly resilient single unified system of up to nine switches, providing simplified management using a single IP
address, single Telnet session, single CLI, auto-version checking, auto-upgrading, auto-configuration, and more.
StackWise-480 also enables local switching in Cisco Catalyst 3850 Series Switches.
Cisco StackPower Technology
The Cisco Catalyst 3850 Series uses the Cisco StackPower technology present on the Cisco Catalyst 3850 Series.
StackPower is an innovative power interconnect system that allows the power supplies in a stack to be shared as a
common resource among all the switches. Cisco StackPower unifies the individual power supplies installed in the
switches and creates a pool of power, directing that power where it is needed. Up to four switches can be
configured in a StackPower stack with the special connector at the back of the switch using the StackPower cable,
which is different than the StackWise-480 cables. (See Figure 5.)
Figure 5. StackWise-480 and StackPower Connectors
StackPower can be deployed in either power-sharing mode or redundancy mode. In power-sharing mode, the
power of all the power supplies in the stack is aggregated and distributed among the switches in the stack. In
redundant mode, when the total power budget of the stack is calculated, the wattage of the largest power supply is
not included. That power is held in reserve and used to maintain power to switches and attached devices when one
power supply fails, enabling the network to operate without interruption. Following the failure of one power supply,
the StackPower mode becomes power sharing.
StackPower allows customers to simply add one extra power supply in any switch of the stack and either provide
power redundancy for any of the stack members or simply add more power to the shared pool. StackPower
eliminates the need for an external redundant power system or installation of dual power supplies in all the stack
members. StackPower is available in LAN Base license level (or higher). For LAN Base, cables need to be
purchased separately.