Slot Numbers; About Redundancy; Placing Summit Family Switches For Stacked Operation - Extreme Networks Summit X250e-24t Hardware Installation Manual

Slot Numbers

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
and configure the stack from the console on the switch at the top of the physical stack, the switches will
be assigned numbers 1 through 8 from the top down.
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.

About Redundancy

When your stack is operational, one switch is the primary (or master) switch that is 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 master if the
master 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 master and slot 2 as the
backup. You can also configure additional switches as "master-capable" to become a stack master in
case the initial backup switch fails.
In a stack with multiple master-capable switches, it is possible for more than one switch to try become
the stack master if the stack is physically severed. Such a dual-master condition would cause confusion
and loss of connectivity in your networks. To resolve a dual-master condition, you must be able to log
in to each severed stack segment, either over the management network (using the Ethernet management
port on a switch in the segment) or through a direct console port connection to each switch in the
segment.
Stack configuration, easy setup, and redundancy are fully described in the ExtremeXOS 12.0 Concepts
Guide.

Placing Summit Family Switches for Stacked Operation

This section summarizes the recommended best practices for installing Summit switches for a
SummitStack configuration. For detailed information about how to configure and manage the stack and
how a stack operates, refer to the ExtremeXOS Concepts Guide.
When you install switches for a SummitStack configuration, follow these recommendations:
Use the shortest possible stacking cables to connect the switches in the stack; this reduces the
●
likelihood that the stacking cables might be accidentally damaged or disconnected. Stacking cables
are available in lengths from 0.3 meters to 5 meters (see
When possible, place all switches for the stack in the same rack; this facilitates using shorter stacking
●
cables.
Because the switches will form a ring, make sure that no two switches in the stack are located more
●
than 5 meters apart.
Summit Family Switches Hardware Installation Guide
"Connecting the Switches to Form the Stack Ring" on page 92
Table 16 on page 90).
91