Installation Guide

Table Of Contents

Figure 35: Switches Connected to Form a Stack

The following sections introduce you to the basic principles of stacking and provide recommendations

for creating stacks.

More information to answer your questions about stacking and help you plan your conﬁguration is

available on the Extreme Networks GTAC Knowledge Base.

Building Basic Stacks

A stack can be created in either of two ways:

• In native stacking, switches are connected using either designated Ethernet data ports or dedicated

stacking connectors.

• In alternate stacking, switches are connected using 10-Gbps Ethernet data ports that have been

conﬁgured for stacking. These ports are located either on the switch itself or on option cards

installed on the rear of the switch.

When planning and building your stack, be sure to follow port compatibility and cabling

recommendations as described in this chapter.

See Combining Switches from Dierent Series on page 63 for information about which switch series

can be combined to form a stack.

Slot Numbers in Stacks

A switch stack can be thought of as a virtual chassis. Each switch (node) operates as if it were

occupying a slot in a chassis and is controlled by the primary. The high-speed stacking links function like

the backplane links of a chassis.

Each switch in the stack is assigned a “slot number” during the initial software conﬁguration of the

stack. Starting at the switch with the console connection, numbers are assigned in numerical order

following the physical path of the connected stacking cables. For example, if you follow the cabling

recommendations presented in Connecting the Switches to Form the Stack Ring on page 65 and

conﬁgure a vertical stack from the console on the switch at the top of the physical stack, the switches

will be assigned slot numbers 1 through 8 from the top down.

Building Basic Stacks

Building Stacks

52 ExtremeSwitching 5520 Series Hardware Installation Guide