• You cannot have a switch stack containing a mix of different license levels. Information About Switch Stacks Switch Stack Overview A switch stack can have up to eight stacking-capable switches connected through their StackWise-480 ports. Note that Cisco Catalyst 9300L series switches connect through their StackWise-320 ports.The stack members work together as a unified system. Layer 2 and Layer 3 protocols present the entire switch stack as a single entity to the network. A switch stack always has one active switch and one standby switch. If the active switch becomes unavailable, the standby switch assumes the role of the active switch, and continues to the keep the stack operational.
The active switch controls the operation of the switch stack, and is the single point of stack-wide management. From the active switch, you configure: • System-level (global) features that apply to all stack members • Interface-level features for each stack member The active switch contains the saved and running configuration files for the switch stack. The configuration files include the system-level settings for the switch stack and the interface-level settings for each stack member. Each stack member has a current copy of these files for back-up purposes. Switch Stack Membership A standalone device is a device stack with one stack member that also operates as the active switch.
You can connect one standalone device to another to create a device stack containing two stack members, with one of them as the active switch. You can connect standalone devices to an existing device stack to increase the stack membership. Hello messages are sent and received by all stack members. • If a stack member does not respond, that member is removed from the stack. • If the standby device does not respond, a new standby device is elected. • If the active device does not respond, the standby device becomes the active device. In addition, keepalive messages are sent and received between the active and standby devicees.
• If the standby device does not respond, a new standby device is elected. • If the active device does not respond, the standby device becomes the active device. Changes to Switch Stack Membership If you replace a stack member with an identical model, the new switch functions with exactly the same configuration as the replaced switch, assuming that the new switch (referred to as the provisioned switch) is using the same member number as the replaced switch. Managing Switch Stacks Information About Switch Stacks Managing Switch Stacks 2