Stacking allows users to physically connect eight individual Summit switches together as a single
logical unit. This logical unit behaves as a single switch with a single IP address and a single point of
authentication.

The stack is controlled by a master switch that always is designated as slot 1. There can only be one
master for a stack. If two switches attempt to become the master, one of the switches fails to create a
stack.

The remaining switches in the stack are considered to be stack members or slaves to the stack master.
Each stack member acts as if it were a slot in a chassis and waits for configuration information from the
stack master. The master stores configuration information for the stack in its primary or secondary flash
memory.

The master has the knowledge of the state and the configuration of all the other switches in the stack
and can respond to all external requests for those switches. For example, slot 1 can respond to a request
for SNMP information from all ports within the stack.

Only Summit 200-24 and 200-48 switches are eligible for participation in a stack. As discussed in
Chapter 2, “Switch Installation” on page 27, the switches are cabled in a daisy chain configuration. This
configuration has the benefit of being able to use the high-speed Gigabit Ethernet ports as uplink ports.

All installations use the high-speed Gigabit Ethernet ports as the dedicated stacking ports. These are
ports 49 and 50 on the S200-48 or port 25 and 26 on the S200-24. The stacking configuration provides
you with two high-speed ports on the end switches for uplinks. If you use the 16 ports as redundant
links with STP, we recommend that you configure the stack master in the middle of the stack. See