Digital Equipment DECbridge 90FL User manual

DECbridge90FL
Owner’sManual
Order Number: EK-DEWGF-OM. A01
Revision/Update Information: This is a new manual.
Digital Equipment Corporation
Maynard, Massachusetts

First Edition, August 1992
The information in this document is subject to change without notice and should not be construed
as a commitment by Digital Equipment Corporation. Digital Equipment Corporation assumes no
responsibility for any errors that may appear in this document.
The software described in this document is furnished under a license and may be used or copied
only in accordance with the terms of such license.
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by Digital Equipment Corporation or its affiliated companies.
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as set forth in subparagraph (c) (1) (ii) of the Rights in Technical Data and Computer Software
clause at DFARS 252.227-7013.
© Digital Equipment Corporation 1992.
All Rights Reserved.
Printed in U.S.A.
FCC NOTICE: The equipment described in this manual generates, uses, and may emit radio
frequency energy. The equipment has been type tested and found to comply with the limits for
a Class A computing device pursuant to Subpart J of Part 15 of FCC Rules, which are designed
to provide reasonable protection against such radio frequency interference when operated in a
commercial environment. Operation of this equipment in a residential area may cause interference,
in which case the user at his own expense may be required to take measures to correct the
interference.
The following are trademarks of Digital Equipment Corporation: BI, DEC, DECbridge, DECconnect,
DECmcc, DECnet, DECserver, Digital, LAT, MicroVAX, ThinWire, ULTRIX, UNIBUS, VAX,
VAX–11/780, VAX–11/785, VAX 3600, VAX 3900, VAX 6000, VAX 6300, VAX 6400, VAX 9000,
VAXcluster, VAX DOCUMENT, VAXELN, VAXstation, VMS, VT, and the DIGITAL logo.
This document was prepared using VAX DOCUMENT, Version 2.0.

Contents
About This Manual...................................... vii
1 Overview
Features ............................................. 1–1
Description ........................................... 1–1
DECbridge 90FL Front Panel Lights and Switches ............ 1–3
2 Configuring the DECbridge 90FL
Supported Configurations. ............................... 2–4
3 Installation
Power Supply . . ....................................... 3–1
Site Considerations .................................... 3–1
Standalone Installation . . ............................... 3–2
Mount the DECbridge 90FL on a Wall ................... 3–4
Make Connections for Standalone Installations ............ 3–6
Backplane Installation . . . ............................... 3–9
Insert the DECbridge 90FL into the DEChub 90
Backplane . ....................................... 3–9
Make Connections for Backplane Installations ............ 3–11
4 Managing the DECbridge 90FL
DECbridge 90FL Operation .............................. 4–1
DECbridge 90FL Functions ........................... 4–2
Spanning Tree Algorithm ............................. 4–3
Spanning Tree Algorithm Properties .................... 4–3
MOP............................................. 4–3
MOP Functions .................................... 4–4
Accessing MOP from VMS Systems ..................... 4–4
iii

Accessing MOP from ULTRIX Systems . . . ............... 4–6
Console Carrier User Interface . ....................... 4–6
Console Carrier Command Language....................... 4–7
Description of Command Parameters .................... 4–9
Description of Commands ............................ 4–10
Protocol Filtering Examples ........................... 4–17
Remote Bridge Management Software (RBMS) ............ 4–19
Error Messages ....................................... 4–20
5 Troubleshooting
Customer Services Option ............................... 5–5
A Specifications and Parts List
Parts List ............................................ A–3
B Related Documentation
Ordering Information ................................... B–1
Continental USA and Puerto Rico ................... B–1
New Hampshire, Alaska, and Hawaii . ............... B–1
Outside the USA and Puerto Rico ................... B–2
Digital Personnel . ............................... B–2
Index
Figures
1–1 Sample DECbridge 90FL Connection .............. 1–3
1–2 Indicators and Connectors ...................... 1–4
2–1 DECbridge 90FL Configured to Fiber-Optic
Backbone ................................... 2–2
2–2 DECbridge 90FL Configured to AUI Backbone ...... 2–3
2–3 Work Group With More Than 200 Stations . . . ...... 2–5
2–4 Redundant Connections . ....................... 2–6
2–5 Bridges in the Work Group ..................... 2–7
2–6 Multiple Bridges in Work Group . . ............... 2–8
3–1 Standalone Installation . ....................... 3–3
3–2 Removing the Back Cover ...................... 3–5
iv

3–3 Connecting Transceiver Cables . . . ............... 3–7
3–4 Connecting to the Middle of a ThinWire Segment .... 3–8
3–5 Connecting to the End of a ThinWire Segment ...... 3–8
3–6 Installing the DECbridge 90FL in DEChub 90
Backplane . . . ............................... 3–10
Tables
4–1 Ethernet Circuit Names for Systems ............. 4–5
4–2 Summary of DECbridge 90FL Commands .......... 4–7
4–3 Protocol Type Codes and Names . . ............... 4–17
4–4 DECbridge 90FL Error Messages. . ............... 4–20
5–1 Activity Indicators (LEDs) ...................... 5–2
5–2 Simple Troubleshooting . ....................... 5–4
A–1 Physical Dimensions . . . ....................... A–1
A–2 Operating Environment . ....................... A–2
A–3 Shipping Environment . . ....................... A–2
A–4 Power Specifications........................... A–2
A–5 Standalone Installation Kit Contents .............. A–3
A–6 DEChub 90 Backplane Installation Kit Contents ..... A–3
v

About This Manual
This manual provides an overview of the DECbridge 90FL unit and describes
how to configure, install, operate, manage, and troubleshoot the DECbridge 90FL.
This manual also provides the specifications and lists the related documentation
for the DECbridge 90FL.
In this manual, the DECbridge 90FL unit may be referred to as the DECbridge 90FL,
work group bridge,bridge,orWGB.
Organization
This manual has five chapters, two appendices, and an index.
Chapter Description
1 Provides an overview of the DECbridge 90FL, including fea-
tures, description of front panel indicators, and configurations
2 Provides configuration rules for the DECbridge 90FL
3 Describes how to install the DECbridge 90FL
4 Describes how to manage the DECbridge 90FL through the
Maintenance Operations Protocol (MOP) or Network Control
Program (NCP)
5 Describes how to troubleshoot the DECbridge 90FL
Appendix A Describes the physical dimensions, the environmental,
electrical, and power specifications, and provides a parts
list
Appendix B Provides a list of related documentation and ordering
information
vii

Conventions
This manual uses the following conventions:
Convention Meaning
Note Provides general information
boldface type Boldface type in examples indicates user input. For example:
DECbridge> SET PROTOCOL
parameters Parameters are italicized. For example:
SHOW PORT slot number
[] Characters within brackets represent optional parameters. For
example:
SHOW PORT [hub number,slot number]
viii

1
Overview
The DECbridge 90FL unit offers a reliable, high-performance, easy-to-install
means of connecting two local area networks (LANs). Configured as a standalone
unit or in the DEChub 90 backplane, the DECbridge 90FL provides greater
network reliability and efficiency by allowing the local area network to be
partitioned into a number of smaller LANs.
Features
The following list summarizes the main features of the DECbridge 90FL:
• Easy-to-use
• Plug-and-go installation
• Activity LEDs for easy diagnosis
• Small size
• Rack-mountable in DEChub 90 backplane
• Frame filtering and frame forwarding at full
network throughput
• Protocol filtering
• Support of spanning tree
algorithm
• Management through Maintenance
Operations Protocol (MOP)
console carrier
• Support of Remote Bridge
Management Software (RBMS)
• Fiber-optic link ports (10Base-FL)
and 15-pin AUI Ethernet
interfaces
Description
The DECbridge 90FL is a specialized LAN device that connects two Ethernet
or IEEE 802.3 LANs to form a single extended local area network (Figure 1–1).
One LAN, referred to as the backbone, can consist of an unrestricted number of
stations. The other LAN, referred to as the work group, is usually the smaller
of the two LANs and is optimized for LANs of fewer than 200 stations.
Overview 1–1

When the work group consists of fewer than 200 stations, the DECbridge 90FL
automatically prevents unnecessary traffic from being transmitted from one
LAN to the other. When there are more than 200 stations in the work group,
the DECbridge 90FL enters flood mode, which reduces the effectiveness of
the traffic isolation, but ensures full connectivity across the bridge. (Refer to
Chapter 4, Management, for further information about flood mode.)
The DECbridge 90FL provides the network manager with additional control over
traffic distribution through protocol filtering and repeater management features.
All stations connected within the extended LAN communicate with one another
as if they were all on the same LAN. The connected LANs will work in networks
using equipment designed to be compatible with the Ethernet or IEEE 802.3
standards. The DECbridge 90FL connects to the work group using a ThinWire
(10Base2) integral transceiver. The backbone connections are made through one
of two user-selectable interfaces: fiber-optic interface (10Base-FL) or 15-pin AUI
Ethernet (10Base5) interface.
The 10Base-FL standard, which is an improved version of the original Fiber
Optic Inter Repeater Link (FOIRL) standard, allows backward compatibility of
the 10Base-FL bridge with a FOIRL transceiver. Bridge operation is transparent
to other stations on the LAN. No special software is required on any station.
Figure 1–1 shows a sample DECbridge 90FL connection.
1–2 Overview

Figure 1–1 Sample DECbridge 90FL Connection
Workstations
DECrepeater 90C
Personal Computer
Work Group ThinWire Segment
DECbridge 90/90FL
Work Group Bridge
Ethernet Backbone
Computer Server
DECrepeater 90T
Workstation
DECserver 90L
Workstation
Computer Computer
Workstations Terminals
Work Group
LJ-02073-TI0
DECbridge 90FL Front Panel Lights and Switches
The front panel of the DECbridge 90FL contains several indicator lights
and two switches (Figure 1–2). The lights (LEDs) indicate the status of the
DECbridge 90FL. One of the switches is a two-way switch that is used to select
either the fiber-optic or AUI port for connection to the backbone; the other switch
is used to reset the DECbridge 90FL password. When you push the reset button,
any existing password is nullified and the DECbridge 90FL is accessible without
a password until you define a new password. For an explanation of the DEFINE
BRIDGE PASSWORD command, refer to the Description of Commands section in
Chapter 4, Management.
Overview 1–3

Figure 1–2 shows the DECbridge 90FL indicators and connectors.
Figure 1–2 Indicators and Connectors
LJ-02074-TI0
17
18
16
19
1
2
3
4
5
6
7
8
9
12
10
11
13
14
15
! DC OK Indicator - (Green) Turns on when power supply is providing
power to the bridge.
1–4 Overview

" System OK Indicator - (Green) Turns on when bridge is powered up and
reset and has successfully completed self-test.
#
Work Group Port OK Indicator - (Green) Turns on when bridge is
powered up and reset and has successfully completed work group port
self-test. Will turn off whenever a fault is detected on the port; turns on
when the fault has been cleared.
$
Work Group Port Activity Indicator - (Green) Blinks when the LAN
connected to the work group port is receiving messages; does not blink
when transmitting messages.
%
1
Bridge Forwarding State - (Yellow) Turns on when bridge is not
forwarding messages. Turns on for a short period of time during power
up. Remains off during normal operation.
&
2
Maximum Work Group Size Exceeded Indicator - (Yellow) Turns on
when the recommended maximum size (200) of the work group has been
exceeded.
'
Link Monitor Indicator - Indicates a successful connection to the fiber-
optic backbone.
(
Backbone Port OK Indicator - (Green) Turns on when the bridge is
powered up and reset and has successfully completed backbone port self-
test. Will turn off whenever a fault is detected on the port; turns on when
fault has been cleared.
)
Backbone Port Activity Indicator - (Green) Blinks when there is
received activity on the LAN connected to the backbone port; does not blink
for transmitted messages.
+>
Fiber Optic Transmit Connector - Connects to the transmit cable,
which is connected to the receiving port of the other fiber-optic device.
+?
Fiber Optic Receive Connector - Connects to the receive cable, which is
connected to the transmitting port of the other fiber-optic device.
+@ Fiber Optic/AUI Selector - Selects fiber-optic or AUI connection to the
backbone.
+A Ethernet Address - Unique physical address of the bridge, comprised of
six 2-digit hexadecimal numbers.
+B Backbone Port AUI Connector - Provides AUI connection to the
backbone port of the DECbridge 90FL.
+C
Password Reset Switch - Nullifies the password for the DECbridge 90FL.
The bridge is accessible without a password until a new password is
defined.
Overview 1–5

+D Work Group Port ThinWire Connector - Provides ThinWire connection
to the work group port of the DECbridge 90FL.
+E Backplane Connector - Provides work group network connection to the
DECbridge 90FL when it is installed in the DEChub backplane.
+F Power Connector - Provides +5.0 and +12.0 V from the DECbridge 90FL
power supply (standalone) or the DEChub 90 power supply (mounted).
+G Cover - Covers the backplane connector and mounting assembly.
1–6 Overview

2
Configuring the DECbridge 90FL
The DECbridge 90FL unit has several configuration rules and guidelines that
must be followed during installation and use.
Each LAN connected by the DECbridge 90FL is required to be an Ethernet or
IEEE 802.3 compliant CSMA/CD LAN. The backbone port of the DECbridge 90FL
provides both fiber-optic (10Base-FL) and AUI (10Base5) connections, as shown
in Figure 2–1 and Figure 2–2. The work group port provides only a ThinWire
(10Base2) connection.
Figure 2–1 shows the DECbridge 90FL configured to a fiber-optic backbone.
Configuring the DECbridge 90FL 2–1

Figure 2–1 DECbridge 90FL Configured to Fiber-Optic Backbone
LJ-02075-TI0
System
System System
System System
50-OHM
Terminator
Backbone Port
F/O Connection
50-OHM
Terminator
Work
Group
Bridge
Rx
Tx
Tx Rx
Rx Tx Rx Tx Rx Tx
50-OHM
Terminator
50-OHM
Terminator
2–2 Configuring the DECbridge 90FL

Figure 2–2 shows the DECbridge 90FL configured to an AUI backbone.
Figure 2–2 DECbridge 90FL Configured to AUI Backbone
H4005
Work
Group
Bridge
50-OHM
Terminator 50-OHM Terminator
50-OHM
Terminator
LJ-02076-TI0
System System System
T-Connector
with Terminator
Transceiver Transceiver
System System
Work Group
Side
Backbone Port
AUI Connector
Configuring the DECbridge 90FL 2–3

Supported Configurations
There are several reasons to configure bridges into an extended LAN:
• To connect different media types. (For example, to connect a fiber-optic
backbone to a ThinWire (10Base2) work group.)
• To extend the range of the LAN. (For example, to attach a DEChub 90 to a
fiber-optic or AUI backbone).
Cable length and repeater configuration rules are considered separately in
each LAN.
• To control traffic by protocol type, by separating the LAN into networks for
selected protocols. (For example, to keep VAXcluster traffic confined within a
work group.)
• To automatically control traffic by keeping messages between stations on the
same LAN from being retransmitted on the other LAN.
The following network configurations may require special consideration:
•Work group size
To automatically isolate traffic, the work group should consist of less than
200 stations. When the number of stations in a work group exceeds 200, the
Work Group Size Exceeded light will come on indicating that flood mode is
enabled (indicator light number 6 shown in Figure 1-2). Refer to Chapter 4,
Management, for further information about flood mode.
To avoid enabling flood mode when a work group consists of more than
200 stations, separate the work group into smaller groups of less than 200
stations each with its own DECbridge 90FL.
Figure 2–3 shows a configuration for a work group with more than 200
stations.
2–4 Configuring the DECbridge 90FL

Figure 2–3 Work Group With More Than 200 Stations
WGB
Work Group
System System
If there are more than 200 stations in a work group,
separate into two work groups.
WGB
System System < 200
Stations
Ethernet Backbone
LJ-02229-TI0
•Redundant connections to the backbone
If two DECbridge 90FL units are configured into a redundant connection
to the backbone, the spanning tree algorithm will allow only one bridge to
forward traffic at a time. However, if a failure occurs in the backbone that
causes the connection to be separated into two LANs, the spanning tree may
reconfigure to pass all backbone traffic through your work group. When this
occurs, the work group side of the bridge may see more than 200 stations and
enter flood mode.
Figure 2–4 shows redundant connections to the backbone.
Configuring the DECbridge 90FL 2–5

Figure 2–4 Redundant Connections
WGB
System System System
Parallel configurations.
Bridge
Ethernet Backbone
LJ-02232-TI0
Work Group
•Bridges in the work group
If there are additional bridges on the work group side of the DECbridge 90FL,
be sure to count the stations on all LANs in the work group against the 200-
station limit and count each bridge as two against the total. In addition, if
any of these bridges lead back to the backbone, the redundant connection may
lead to spanning trees that exceed 200 stations on the work group side of the
DECbridge 90FL.
Figure 2–5 shows bridges in the work group.
2–6 Configuring the DECbridge 90FL