Summitstack Topologies - Extreme Networks Extreme 7520 Series Hardware Installation Manual

SummitStack Topologies

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
the Switches to Form the Stack Ring
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.
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 might 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.
Primary/Backup Switch Redundancy
When your stack is operational, one switch is the primary switch, responsible for
running network protocols and managing the stack.
To provide recovery in case of a break in the stack connections, you can configure
redundancy by designating a backup switch to take over as primary if the primary
switch fails. When you perform the initial software configuration of the stack, the
"easy setup" configuration option automatically configures redundancy, with slot 1 as
the primary and slot 2 as the backup. You can also configure additional switches as
"primary-capable," meaning they can become a stack primary in case the initial backup
switch fails.
SummitStack Topologies
Figure 6
describe stack conditions.
22 Extreme 7520 Hardware Installation Guide
presents a graphical representation of a stack and some of the terms that
on page 33 and configure a vertical stack from
Build Stacks
Connect