3Com SuperStack 3870 User manual

Introducing the Resilient Stacking Cable
The Resilient Stacking Cable enables you to stack together
two switches, up to sixteen rack units apart. You can stack
any combination of 3870 24 and 48 port switches, up to a
maximum of eight units.
The Stacking Cable is 130 cm (51.2 in.) long and marked
with a yellow label for the Up and a blue label for the
Down D-Type connectors.
Only one switch in the stack can operate as the master
switch, all other switches operate in slave mode. If more
than one switch in the stack is selected as the master, or if
no switches are selected, the stack will not operate.
Figure 1 The Resilient Stacking Cable
Installing the Stacking Cable
Connect the Stacking Cable as shown in Figure 2.
Always secure the Stacking Cable to the device by tighten-
ing its securing screws.
CAUTION: If a Resilient Stacking Cable is not fitted then dis-
connecting a Stacking Cable (when the stack is in use) will
break the flow of data.
Figure 2 Connecting Switches in a Stack
Down Connector (Blue Label)
Up Connector (Yellow Label)
Securing Screws
!
!
UP
DOWN
UP
DOWN
UP
DOWN
UP
DOWN
SuperStack®3 Switch 3870 Resilient Stacking Cable
(3C17463)
Installation Guide
DUA1746_3AAA01.fm Page 1 Monday, April 26, 2004 11:43 AM

Table 1 Attaching the Cable Between Two Switches
LEDs
The stack LEDs are located on the front of the Switch as
shown in Figure 3:
Figure 3 Switch Front Panel - Stack LEDs
Table 2 shows how to read the status of the stack according
to the stack LEDs on the front of the Switch.
Table 2 Stack LEDs
© 3Com Technologies, 2004. All rights reserved. No part of this documentation may be reproduced in
any form or by any means or used to make any derivative work (such as translation, transformation, or
adaptation) without permission from 3Com Technologies.
3Com, the 3Com logo and SuperStack are registered trademarks of 3Com Corporation. Unless
otherwise indicated, 3Com registered trademarks are registered in the United States and may or may
not be registered in other countries.
Part No. DUA1746-3AAA01 Published May 2004
Connector Label Color Attach to the:
Yellow Up port in the back panel of the top Switch
Blue Down port in the back panel of the bottom
Switch
SuperStack 3 Switch 3870 24-port
Stack
Master
Module
Activity
21 22 23 24
S
S
Power
Fault
P
Stack Status/
Stack Master LEDs
Color State:
Status
Green The Uplink/Downlink is operating normally.
Yellow One-sided connection (one side of the cable is connected
but the other side is not).
Off No stacking link is present.
Master
Green Master unit - normal stack operation state.
Yellow Slave unit - normal stack operation state.
Yellow flashing The system is in arbitration/election state.
Off The system is not stacked.
DUA1746_3AAA01.fm Page 2 Monday, April 26, 2004 11:43 AM