Extreme x250e-24t Installation Instruction

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Summit Family Switches Hardware Installation Guide
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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
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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.