Confidential and proprietary information of Extreme Networks. © 2011 Extreme Networks, Inc.
All rights reserved. DRAFT. October 20, 2011
Building a SummitStack Configuration
Summit Family Switches Hardware Installation Guide
152
Figure 103: Summit Switches Connected in a SummitStack Configuration
The stack operates as a single switch with a single IP address and a single point of authentication. One
switch, called the stack master, controls the stack. The master runs ExtremeXOS software and maintains
all the software tables for all the switches in the stack. A stack of switches can have only one master
switch. All switches in the stack, including the master switch, are called nodes.
Slot Numbers
A stack can be thought of as a virtual chassis. Each node operates as if it were occupying a slot in a
chassis and is controlled by the master. The high-speed stacking links function like the backplane links
of a chassis.
Each switch (or node) 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 159
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, starting with slot 1.
Figure 104: Assigned Slot Numbers in a Stack
Each Summit switch has a seven-segment LED on its front panel, called the stack number indicator.
When a stack is operating, the indicator displays the slot number for the switch. This LED does not
light on switches that are not operating in stacking mode. A quick way to verify that the cable
connections match the software configuration is to check the stack number indicator on each switch. If
the slot numbers do not line up in the order you arranged the switches, this may indicate that the
stacking cable setup differs from what you intended when you configured the software. In this case,
reconnect the cables in the correct order and perform the software configuration again.
Stack Port 1
Stack Port 2
Stack Port 1
Stack Port 2
Stack Port 1
Stack Port 2
Stack Port 1
Stack Port 2
SH_176
Summit
switches
SummitStack
cables
BD_164A
Slot 1
Slot 2
Slot 3
Slot 4
