Installation Guide

Table Of Contents

Some stackable switches have a seven-segment LED, called the stack number indicator on the front

panel. (See Figure 115.) When a stack is operating, the indicator displays the switch's slot number. This

LED does not light on switches that are not currently operating as part of a stack.

The top half of the number blinks if the switch is the master, and the bottom half blinks if it is the

backup. If the LED is steadily lit, the switch is a standby. If the LED is o the switch is not conﬁgured as a

member of a stack.

Figure 115: Position of the Stack Number Indicator (X460-G2 Switch Shown)

In addition to the Stack Number Indicator, each stacking port has an LED. The LED is steady green if the

link is OK, blinking green if trac is present, and o if no signal is present.

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 diers 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.

Master/Backup Switch Redundancy

When your stack is operational, one switch is the master 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 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,” meaning they can become a stack master in case the initial

backup switch fails.

When assigning the master and backup roles in mixed stacks, consider the feature scalability and the

speed of each switch model. The easy setup conﬁguration process selects master and backup switches,

based on capability and speed, in the following order:

1 Summit X670-G2

2 Summit X460-G2

3 Summit X770

4 Summit X450-G2

5 ExtremeSwitching X440-G2 and X620

For example, in a stack that combines Summit X460-G2 or X670-G2 switches with other switch models,

an X460-G2 or X670-G2 switch might provide more memory and more features than other switches in

Building Stacks

ExtremeSwitching and Summit Switches: Hardware Installation Guide 138