Bay Networks BayStack 400-ST1 User manual

Part No. 304433-A Rev 00
November 1998
Installing the
BayStack 400-ST1
Cascade Module

© 1998 by Bay Networks, Inc.
All rights reserved.
Trademarks
Bay Networks is a registered trademark and BayStack is a trademark of Bay
Networks, Inc. All other trademarks and registered trademarks are property of their
respective owners.
Statement of Conditions
In the interest of improving internal design, operational function, and/or reliability,
Bay Networks, Inc. reserves the right to make changes to the products described in
this document without notice.
Bay Networks, Inc. does not assume any liability that may occur due to the use or
application of the product(s) or circuit layout(s) described herein.
Federal Communications Commission (FCC) Compliance Notice:
Radio Frequency Notice
Note: This equipment has been tested and found to comply with the limits for a
Class A digital device, pursuant to Part 15 of the FCC rules. These limits are
designed to provide reasonable protection against harmful interference when the
equipment is operated in a commercial environment. This equipment generates,
uses, and can radiate radio frequency energy. If it is not installed and used in
accordance with the instruction manual, it may cause harmful interference to radio
communications. Operation of this equipment in a residential area is likely to cause
harmful interference, in which case users will be required to take whatever
measures may be necessary to correct the interference at their own expense.
EN 55 022 Declaration of Conformance (UPDATE THIS FOR 400-ST1)
This is to certify that the Bay Networks BayStack 400-ST1 Cascade Module are
shielded against the generation of radio interference in accordance with the
application of Council Directive 89/336/EEC, Article 4a. Conformity is declared by
the application of EN 55 022 Class A (CISPR 22).
Warning: This device is a Class A product. In a domestic environment, this product
may cause radio interference, in which case, the user may be required to take
appropriate measures.
These products conform to the provisions of Council Directive 89/336/EEC and
72/23/EEC. The Declaration of Conformity is available on the Bay Networks World
Wide Web site at www.baynetworks.com.

1
Introduction
This guide provides procedures for installing the BayStack
400-ST1 Cascade Modules into supported Bay Networks
BayStack 450 switches that are configured with BayStack
450 software version V1.1.0 or later. You can determine
the software version of your switches by accessing the
System Characteristics screen for each switch.
If you need to upgrade your BayStack 450 switches, refer
to “Upgrading the BayStack 450 Switch Firmware” on
page 36 of this guide. You must upgrade the switch before
installing the BayStack 400-ST1 Cascade Module.
If you are upgrading your BayStack 450 switches, be sure
to obtain the latest version of the Using the BayStack 450
10/100/1000 Series Switch guide. That guide provides
instructions for setting up your stack configuration after
you install the 400-ST1 Cascade Modules.
You can obtain the latest updates to your product
documentation, including release notes, by visiting the
Bay Networks Web site at the following location:
www.support.baynetworks.com/library/tpubs
Note: The BayStack 400-ST1 Cascade Module
will not operate with BayStack 450 switches that
are configured with BayStack 450 software
versions earlier than version V1.1.0.

2
Find the Bay Networks product for which you need
documentation. Then locate the specific category and
model or version for your hardware or software product.
Using Adobe Acrobat Reader, you can open the manuals
and release notes, search for the sections you need, and
print them on most standard printers. You can download
Acrobat Reader free from the Adobe Systems Web site,
www.adobe.com.
This guide also describes how to connect 400-ST1
Cascade Modules to create a stack of (up to eight)
BayStack 450 switches, and how to modify existing stack
configurations.
For information about: Go to page:
The contents of the shipping box 3
The 400-ST1 front panel components 4
The base unit 7
Stack configurations 10
The redundant cascade stacking feature 14
Installing the 400-ST1 Cascade Module 16
Modifying an existing stack configuration 26
Upgrading the BayStack 450 Switch
Firmware 36

3
Contents of Shipment
Each BayStack 400-ST1 shipment includes the following
items (Figure 1):
• One BayStack 400-ST1 Cascade Module
• One .30 meter (12 inch) cascade cable; part number
303978-A.
•This guide (Installing the BayStack 400-ST1 Cascade
Module).
Figure 1. Contents of Shipment
For stacking three or more units (maximum 8 units per
stack), order the optional 1 meter (39.27 inch) cascade
max-return cable (Bay Networks Order No. AL2018001).
BS0030A
BayStack 400-ST1
cascade module
0.30 m (12 in.) cascade
cable (PN 303978-A)
Optional:
1 m (39.27 in.)
cascade max-return
cable (PN 303979-A)
Installing the BayStack 400-ST1
Cascade Module

4
If any items are missing or damaged, contact the sales
agent or the customer service representative from whom
you purchased the BayStack 400-ST1 cascade module.
You will need a Phillips screwdriver for the installation.
BayStack 400-ST1 Front Panel Components
The front-panel components of the BayStack 400-ST1
Cascade Module are shown in Figure 2. Component
descriptions follow the figure.
Figure 2. Front Panel Components
Note: Unless otherwise specified, the terms
“switch” and “unit” are used interchangeably in
this guide.
Cascade A Out Cascade A In
Unit Select
Base
1 = Blank connectors (unused)
2 = Cascade A Out connector
3 = Unit Select switch
4 = Cascade A In connector
3
BS0031A
4
1
2

5
Cascade A Out Connector
Provides an attachment point for connecting this unit to
another unit via the cascade cable. A return cable from
another unit’s Cascade A Out connector to this unit’s
Cascade A In connector completes the stack connection
(see the example shown in Figure 3).
Unit Select Switch
The Unit Select switch (up = Base) determines the base
unit for the stack configuration (see “Base Unit
Description” on page 7). The Unit Select switch status is
displayed on the BayStack 450 LED display panel (see the
Using the BayStack 450 10/100/1000 Series Switch guide
for details). When in the Base (up) position, all other Unit
Select switches in the stack configuration must be set to
Off (down).
Note: For stacking three or more units
(maximum 8 units per stack), order the optional
1 meter (39.27 inch) cascade max-return cable
(Bay Networks Order No. AL2018001).

6
Cascade A In Connector
Provides an attachment point for accepting a cascade cable
connection from an adjacent unit in the stack. A return
cable from this unit’s Cascade A Out connector to the
adjacent unit’s Cascade A In connector completes the
stack connection (see the example shown in Figure 3).
Figure 3. Connecting Cascade Cables
Cascade A Out
Unit 1
Cascade A Out Cascade A In
Unit 2
1 = Base unit
2 = 303978-A cascade cable
3 = 303978-A cascade cable (used for return) BS0032A
Cascade A InUnit Select
Cascade A Out Cascade A InUnit Select
2
3
1

7
Base Unit Description
The base unit is a unique stack unit that can be selected by
the Unit Select switch on the front-panel of the 400-ST1
cascade module. One unit in the stack configuration must
be assigned as the base unit; all other units in the stack
must have their Unit Select switch set to Off (see “Unit
Select Switch” on page 5). Any single unit in the stack can
be assigned as the base unit.
The physical ordering of all of the other units in the stack
are determined by the position of the base unit within the
stack. This is important for management applications that
view the physical ordering of the units within the stack.
Some characteristics of the base unit are:
•Initial installation --- during the initial installation of
the stack, the software automatically determines the
physical order of all units in the stack according to the
position of the base unit within the stack.
For example, when the stack is powered up, the base
unit becomes unit 1 and the unit that the base unit
connects to (via the Cascade A Out cable) becomes
unit 2 (and the next unit is unit 3 and so on), until the
maximum stack configuration (up to 8 units) is
reached.
If the base unit is changed to another unit in the stack,
the new base unit keeps its original unit number in the
stack.

8
•Stack IP MAC address --- The stack IP MAC address is
automatically assigned during the stack initialization:
The base unit’s MAC address, with a software offset,
is used for the stack IP MAC address.
For example, if the base unit’s MAC address is:
00-00-82-99-44-00
and the Stack software offset is: 1F
then the Stack IP MAC address becomes:
00-00-82-99-44-1F
If another unit in the stack is assigned as the base unit,
the MAC address of the new base unit (with offset)
now applies to the stack configuration. The original
stack IP address still applies to the new base unit.
Note: You can renumber the units when you
perform the initial setup of the stack as described
in the Using the BayStack 450 10/100/1000
Series Switch guide.

9
• Temporary Base Unit --- If an assigned base unit fails,
the next unit in the stack order automatically becomes
the new temporary base unit. This change is indicated
by the Base LED on the temporary base unit’s LED
display panel turning on (yellow).
The automatic base unit change to the next unit in the
stack order is a temporary safeguard which allows
you time to replace the failed unit, or reassign the
temporary base unit as the new base unit.
Set the Unit Select switch on the temporary base unit
to Base (up =Base) to reassign it as the new base unit.
•Removing a unit from the stack--- if a unit is removed
from the stack (therefore operating in standalone
mode), the following switch configuration settings
revert back to the settings configured before the unit
became a member of the stack:
• IP address
• console password
• TELNET password
• SNMP community strings
Note: If you do not reassign the temporary base
unit as the new base unit, and the temporary base
unit fails, the automatic failover to another
temporary base unit will not occur.

10
Stack Configurations
As shown in Figure 4, the cascade connectors and cables
on the 400-ST1 front-panel provide the ability to stack up
to eight BayStack switches. With 400-4TX MDAs
installed in each switch, the stack can accommodate a
maximum of 224 switch ports.
Because stack parameters are associated with the base unit
(see “Base Unit Description” on page 7), the physical
stack order depends on the base unit’s position and
whether the stack is configured stack up or stack down.
Stack Up Configurations
In Figure 4, data flows from the base unit (unit 1) to the
next switch, which is assigned as unit 2, and continues
until the last switch in the stack is assigned as unit 8. The
physical order of the switches is from bottom to top (unit 1
to unit 8).
Stack Down Configurations
In Figure 5, data flows from the base unit (unit 1) to the
next switch, which is assigned as unit 2, and continues
until the last switch in the stack is assigned as unit 8. The
physical order of the switches is from top to bottom (unit 1
to unit 8).

11
Figure 4. Stack Up Configuration Example
Unit 7
Unit 8
1 = Last unit
2 = Base unit
3 = Cascade cable (PN 303978-A)
4 = Cascade max-return cable (PN 303979-A)
BS0033A
Unit 5
Unit 6
Unit 3
Unit 4
Unit 1
Unit 2
2
1
3
O
u
t
I
n
4

12
Figure 5. Stack Down Configuration Example
Unit 2
1 = Base unit
2 = Last unit
3 = Cascade cable (PN 303978-A)
4 = Cascade max-return cable (PN 303979-A)
BS0034A
Unit 1
Unit 4
Unit 3
Unit 6
Unit 5
Unit 8
Unit 7
2
1
I
n
O
u
t
4
3

13
Certain network management station (NMS) applications
assume a stack down configuration for the graphical user
interface (GUI) that represents the stack (see Figure 5 on
page 12). For this reason, Bay Networks recommends that
you always configure the top unit in the stack as the base
unit.
In any stack configuration, the following applies:
• The entire stack powers up as a single logical unit
within 30 seconds after the base unit initialization.
• You can attach an RS-232 communications cable to
the Console/Comm port of any switch in the stack.
• You can downline upgrade the entire stack from any
switch in the stack.
• You can access and manage the stack using a
TELNET connection or any generic SNMP
management tool through any switch port that is part
of the stack configuration.
• When stacking three or more switches, the longer
(1-meter) cascade max-return cable (PN 303979-A) is
used to complete the link from the last unit in the
stack to the base unit.

14
Redundant Cascade Stacking Feature
BayStack 400-ST1 Cascade Modules allow you to connect
up to 8 units into a redundant cascade stack. If any single
unit fails or if a cable is accidently disconnected, other
units in the stack remain operational, without interruption.
Figure 6 shows an example of how a stack configuration
reacts to a failed or powered down unit in the stack
configuration:
a. As shown in Figure 6 unit 3 becomes
nonoperational.
This can be the result of a failed unit, or simply
because the unit was powered down.
b. Unit 2 and unit 4, directly upstream and
downstream from unit 3, sense the loss of link
signals from unit 3.
c. Unit 2 and unit 4 automatically loop their
internal stack signals (A and B).
The Cas Up LED for unit 2 and the Cas Dwn
LED for unit 4 turn on (yellow) to indicate the
stack signals are looped.
d. The remaining stack units remain connected.
Although the example shown in Figure 6 shows a failed
unit causing the stack to loop signals at the points of
failure (A and B), the system reacts the same way if a
cable is removed (either deliberately or accidently).

15
Figure 6. Redundant Cascade Stacking Feature
Unit 2
1 = Base unit
2 = Last unit
3 = Cascade cable (PN 303978-A)
4 = Cascade max-return cable (PN 303979-A)
BS0035A
Cascade A Out Cascade A In
Unit 1
Unit 5
Unit 4
Unit 3
2
1
B
A
4
3

16
Installation
This section describes how to connect up to eight
BayStack 10/100/1000 Series switches into a redundant
stack. The switch stack can consist of any combination of
BayStack 450-24T and BayStack 450-12T switch models.
Before installing your equipment, review the previous
sections of this guide.
This section includes the following topics:
• Installing the 400-ST1 Cascade Module
• Installing and connecting multiple switches
• Connecting power
• Verifying the installation
After verifying the installation as described in
“Verifying the Installation” on page 24 of this guide, refer
to the Using the BayStack 450 10/100/1000 Series Switch
guide to set up the stack and customize the stack
configuration according to your system requirements.
Note: For stacking three or more units
(maximum 8 units per stack), order the optional
1 meter (39.27 inch) cascade max-return cable
(Bay Networks Order No. AL2018001).

17
Installing the 400-ST1 Cascade Module
The Cascade Module slot on the BayStack 450 switch can
accommodate a single 400-ST1 Cascade Module.
To install a 400-ST1 Cascade Module into the Cascade
Module slot, follow these steps:
1. Unplug the AC power cord from the back of the
switch.
2. Loosen the thumbscrews and remove the filler
panel from the Cascade Module slot (Figure 7).
Figure 7. Removing the Filler Panel
3. Insert the 400-ST1 Cascade Module into the
chassis slot taking care to slide the module into the
guides provided on the chassis (Figure 8).
BS0036A
1 = Filler panel
2 = Cascade module slot
12

18
Figure 8. Installing a 400-ST1 Cascade Module
4. Press the module firmly into the chassis slot. Be
sure that the module is fully seated into the mating
connector.
5. Secure the module in the chassis by tightening the
thumb screws on the module front panel.
6. Repeat Steps 1 to 5 for each switch that is to be
configured with the 400-ST1 Cascade Module.
7. Proceed to the next section “Installing and
Connecting Multiple Switches” on page 19.
Caution: Be sure that the module slides in on the
guides provided. Failure to align the guides could
result in bent and broken pins
Cascade A Out Cascade A In
Unit Select
Base
BS0037A