Juniper EX9251 User Manual

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EX9251 Switch Hardware Guide

Published

2021-01-31

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Juniper Networks, Inc. 1133 Innovation Way Sunnyvale, California 94089 USA 408-745-2000 www.juniper.net

Juniper Networks, the Juniper Networks logo, Juniper, and Junos are registered trademarks of Juniper Networks, Inc. in the United States and other countries. All other trademarks, service marks, registered marks, or registered service marks are the property of their respective owners.

Juniper Networks assumes no responsibility for any inaccuracies in this document. Juniper Networks reserves the right to change, modify, transfer, or otherwise revise this publication without notice.

EX9251 Switch Hardware Guide

The information in this document is current as of the date on the title page.

YEAR 2000 NOTICE

Juniper Networks hardware and software products are Year 2000 compliant. Junos OS has no known time-related limitations through the year 2038. However, the NTP application is known to have some difficulty in the year 2036.

END USER LICENSE AGREEMENT

The Juniper Networks product that is the subject of this technical documentation consists of (or is intended for use with) Juniper Networks software. Use of such software is subject to the terms and conditions of the End User License Agreement (“EULA”) posted at https://support.juniper.net/support/eula/. By downloading, installing or using such software, you agree to the terms and conditions of that EULA.

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About the Documentation | xi

Documentation and Release Notes | xi

Using the Examples in This Manual | xi

Merging a Full Example | xii

Merging a Snippet | xiii

Documentation Conventions | xiii

Documentation Feedback | xvi

Requesting Technical Support | xvi

Self-Help Online Tools and Resources | xvii

Creating a Service Request with JTAC | xvii

iii

Overview

EX9251 System Overview | 19

EX9251 Switch Hardware Overview | 19

Software | 20

Benefits of the EX9251 Switch | 20

EX9251 Switch Models | 20

Front Panel of an EX9251 Switch | 20

Rear Panel of an EX9251 Switch | 22

Routing Engine | 22

Power Supplies | 23

Cooling System | 23

Component Redundancy | 23

EX9251 Switch Models | 24

EX9251 Switch Hardware and CLI Terminology Mapping | 24

EX9251 Chassis | 26

Chassis Physical Specifications of an EX9251 Switch | 26

Field-Replaceable Units in an EX9251 Switch | 27

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LEDs on the Front Panel of an EX9251 Switch | 27

EX9251 Cooling System | 33

Fan Trays | 33

Airflow Direction in the EX9251 Switch Chassis | 34

Cooling System in the Power Supplies | 35

Fan Tray Status LEDs | 35

EX9251 Power System | 36

Power Supplies in an EX9251 Switch | 36

AC Power Supply Description | 37

AC Power Supply LEDs and Other Components | 38

DC Power Supply Description | 40

DC Power Supply LEDs and Other Components | 40

AC Power Cord Specifications for an EX9251 Switch | 42

Power Requirements for EX9251 Switch Components | 44

Calculating System Thermal Output | 45

Power Supply Specifications for EX9251 Switches | 45

Site Planning, Preparation, and Specifications

Site Preparation Checklist for an EX9251 Switch | 48

EX9251 Site Guidelines and Requirements | 49

Environmental Requirements and Specifications for EX Series Switches | 49

General Site Guidelines | 54

Site Electrical Wiring Guidelines | 55

Clearance Requirements for Airflow and Hardware Maintenance for EX9251 Switches | 56

Rack and Cabinet Requirements for EX9251 Switches | 57

EX9251 Network Cable and Transceiver Planning | 60

Pluggable Transceivers Supported on EX9251 Switches | 60

SFP+ Direct Attach Copper Cables for EX Series Switches | 61

Cable Specifications | 62

List of DAC Cables Supported on EX Series Switches | 62

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Standards Supported by These Cables | 63

QSFP+ Direct Attach Copper Cables for EX Series Switches | 63

Cable Specifications | 64

DAC Cables Supported on EX3400, EX4300, EX4550, EX4600, EX9251, and EX9253

Switches | 64

Understanding EX Series Switches Fiber-Optic Cable Signal Loss, Attenuation, and

Dispersion | 64

Signal Loss in Multimode and Single-Mode Fiber-Optic Cable | 65

Attenuation and Dispersion in Fiber-Optic Cable | 65

Calculating the Fiber-Optic Cable Power Budget for EX Series Devices | 66

Calculating the Fiber-Optic Cable Power Margin for EX Series Devices | 66

EX9251 Management Cable Specifications and Pinouts | 68

Management Cable Specifications | 69

Specifications of Cables and Wires That Connect to Ports on the Front Panel in an EX9251

Switch | 69

Grounding Cable and Lug Specifications for EX9251 Switches | 70

Grounding Points Specifications for an EX9251 Switch | 70

Grounding Cable Specifications for an EX9251 Switch | 71

Grounding Lug Specifications for an EX9251 Switch | 71

USB Port Specifications for an EX Series Switch | 71

Console Port Connector Pinout Information for an EX9251 Switch | 72

RJ-45 to DB-9 Serial Port Adapter Pinout Information | 73

RJ-45 Management Port Connector Pinout Information | 73

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Initial Installation and Configuration

Unpacking and Mounting the EX9251 Switch | 76

Unpacking an EX9251 Switch | 76

Parts Inventory (Packing List) for an EX9251 Switch | 77

Installing and Connecting an EX9251 Switch | 79

Mounting an EX9251 Switch on a Rack or Cabinet | 80

Mounting an EX9251 Switch on a 19-in. Rack | 81

Installing an EX9251 Switch in an ETSI Rack | 84

Connecting the EX9251 to Power | 88

Connect Earth Ground to an EX Series Switch | 88

Parts and Tools Required for Connecting an EX Series Switch to Earth Ground | 89

Special Instructions to Follow Before Connecting Earth Ground to an EX Series Switch | 93

Connecting Earth Ground to an EX Series Switch | 94

Connecting AC Power to an EX9251 Switch and Powering on the Switch | 95

Connecting DC Power to an EX9251 Switch and Powering on the Switch | 99

Connecting the EX9251 to External Devices | 103

Connect a Device to a Network for Out-of-Band Management | 103

Connect a Device to a Management Console Using an RJ-45 Connector | 104

Connecting the EX9251 Switch to External Clocking and Timing Devices | 105

Connecting 1-PPS and 10-MHz Timing Devices to the Switch | 106

Connecting a Time-of-Day Device to the Switch | 107

Connecting a BITS External Clocking Device to the Switch | 107

Connecting the EX9251 to the Network | 108

Install a Transceiver | 108

Connect a Fiber-Optic Cable | 111

Configuring Junos OS on the EX9251 | 112

EX9251 Switch Default Configuration | 112

Connecting and Configuring an EX9251 Switch (CLI Procedure) | 113

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Maintaining Components

Routine Maintenance Procedures for EX9251 Switches | 119

Maintaining the Routing Engine in EX9251 Switches | 119

Maintaining the EX9251 Cooling System | 121

Removing a Fan Tray from an EX9251 Switch | 121

Installing a Fan Tray in an EX9251 Switch | 122

Maintaining Fan Trays in EX9251 Switches | 124

Maintaining the EX9251 Power System | 125

Powering Off an EX9251 Switch | 125

Removing an AC Power Supply from an EX9251 Switch | 126

Installing an AC Power Supply in an EX9251 Switch | 128

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Removing a DC Power Supply from an EX9251 Switch | 129

Installing a DC Power Supply in an EX9251 Switch | 131

Maintaining Power Supplies in EX9251 Switches | 133

Maintaining Transceivers | 134

Remove a Transceiver | 135

Install a Transceiver | 138

Remove a QSFP28 Transceiver | 140

Install a QSFP28 Transceiver | 142

Maintain Fiber-Optic Cables | 144

Connect a Fiber-Optic Cable | 144

Disconnect a Fiber-Optic Cable | 145

How to Handle Fiber-Optic Cables | 146

Troubleshooting Hardware

Troubleshooting EX9251 Components | 149

Troubleshooting the Cooling System in an EX9251 Switch | 149

Troubleshooting Power Supplies in an EX9251 Switch | 150

Troubleshoot Temperature Alarms in EX Series Switches | 151

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Contacting Customer Support and Returning the Chassis or Components

Returning an EX9251 Chassis or Components | 158

Returning an EX9251 Switch or Component for Repair or Replacement | 158

Locating the Serial Number on an EX9251 Switch or Component | 159

Locating the Serial Number ID Label on an EX9251 Switch Chassis | 159

Locating Serial Number ID Labels on FRU Components | 159

Contact Customer Support to Obtain Return Material Authorization | 161

Packing an EX9251 Switch or Component | 162

Packing an EX9251 Switch | 162

Packing EX9251 Switch Components for Shipping | 163

Safety and Compliance Information

General Safety Guidelines and Warnings | 167

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Definitions of Safety Warning Levels | 168

Qualified Personnel Warning | 171

Warning Statement for Norway and Sweden | 172

Fire Safety Requirements | 172

Fire Suppression | 172

Fire Suppression Equipment | 172

Installation Instructions Warning | 174

Chassis and Component Lifting Guidelines | 174

Restricted Access Warning | 176

Ramp Warning | 178

Rack-Mounting and Cabinet-Mounting Warnings | 179

Grounded Equipment Warning | 185

Radiation from Open Port Apertures Warning | 186

Laser and LED Safety Guidelines and Warnings | 187

General Laser Safety Guidelines | 187

Class 1 Laser Product Warning | 188

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Class 1 LED Product Warning | 189

Laser Beam Warning | 190

Maintenance and Operational Safety Guidelines and Warnings | 190

Battery Handling Warning | 192

Jewelry Removal Warning | 193

Lightning Activity Warning | 195

Operating Temperature Warning | 196

Product Disposal Warning | 198

General Electrical Safety Guidelines and Warnings | 199

Action to Take After an Electrical Accident | 200

Prevention of Electrostatic Discharge Damage | 201

AC Power Electrical Safety Guidelines | 202

AC Power Disconnection Warning | 204

DC Power Electrical Safety Guidelines | 205

DC Power Disconnection Warning | 206

DC Power Grounding Requirements and Warning | 208

DC Power Wiring Sequence Warning | 210

DC Power Wiring Terminations Warning | 213

Multiple Power Supplies Disconnection Warning | 216

TN Power Warning | 217

Agency Approvals for EX9251 Switches | 217

Compliance Statements for EMC Requirements for EX Series Switches | 219

Canada | 219

Taiwan | 220

European Community | 220

Israel | 220

Japan | 221

Korea | 221

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United States | 221

FCC Part 15 Statement | 222

Nonregulatory Environmental Standards | 222

Compliance Statements for Acoustic Noise for EX Series Switches | 223

Statements of Volatility for Juniper Network Devices | 224

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About the Documentation

IN THIS SECTION

Documentation and Release Notes | xi

Using the Examples in This Manual | xi

Documentation Conventions | xiii

Documentation Feedback | xvi

Requesting Technical Support | xvi

Use this guide to install hardware and perform initial software configuration, routine maintenance, and troubleshooting for the EX9251 switch. After completing the installation and basic configuration procedures covered in this guide, refer to the Junos OS documentation for information about further software configuration.

Documentation and Release Notes

To obtain the most current version of all Juniper Networks®technical documentation, see the product documentation page on the Juniper Networks website at https://www.juniper.net/documentation/.

If the information in the latest release notes differs from the information in the documentation, follow the product Release Notes.

Juniper Networks Books publishes books by Juniper Networks engineers and subject matter experts. These books go beyond the technical documentation to explore the nuances of network architecture, deployment, and administration. The current list can be viewed at https://www.juniper.net/books.

Using the Examples in This Manual

If you want to use the examples in this manual, you can use the load merge or the load merge relative command. These commands cause the software to merge the incoming configuration into the current candidate configuration. The example does not become active until you commit the candidate configuration.

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If the example configuration contains the top level of the hierarchy (or multiple hierarchies), the example is a full example. In this case, use the load merge command.

If the example configuration does not start at the top level of the hierarchy, the example is a snippet. In this case, use the load merge relative command. These procedures are described in the following sections.

Merging a Full Example

To merge a full example, follow these steps:

1. From the HTML or PDF version of the manual, copy a configuration example into a text file, save the file with a name, and copy the file to a directory on your routing platform.

For example, copy the following configuration to a file and name the file ex-script.conf. Copy the ex-script.conf file to the /var/tmp directory on your routing platform.

system {

scripts {

commit {

file ex-script.xsl;

}

} } interfaces {

fxp0 {

disable; unit 0 {

family inet {

address 10.0.0.1/24;

}

} }

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2. Merge the contents of the file into your routing platform configuration by issuing the load merge configuration mode command:

[edit] user@host# load merge /var/tmp/ex-script.conf load complete

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Merging a Snippet

To merge a snippet, follow these steps:

1. From the HTML or PDF version of the manual, copy a configuration snippet into a text file, save the file with a name, and copy the file to a directory on your routing platform.

For example, copy the following snippet to a file and name the file ex-script-snippet.conf. Copy the ex-script-snippet.conf file to the /var/tmp directory on your routing platform.

commit {

file ex-script-snippet.xsl; }

2. Move to the hierarchy level that is relevant for this snippet by issuing the following configuration mode command:

[edit] user@host# edit system scripts [edit system scripts]

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3. Merge the contents of the file into your routing platform configuration by issuing the load merge relative configuration mode command:

[edit system scripts] user@host# load merge relative /var/tmp/ex-script-snippet.conf load complete

For more information about the load command, see CLI Explorer.

Documentation Conventions

Table 1 on page xiv defines notice icons used in this guide.

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Table 1: Notice Icons

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DescriptionMeaningIcon

Indicates important features or instructions.Informational note

Caution

Indicates a situation that might result in loss of data or hardware damage.

Alerts you to the risk of personal injury or death.Warning

Alerts you to the risk of personal injury from a laser.Laser warning

Indicates helpful information.Tip

Alerts you to a recommended use or implementation.Best practice

Table 2 on page xiv defines the text and syntax conventions used in this guide.

Table 2: Text and Syntax Conventions

ExamplesDescriptionConvention

Fixed-width text like this

Italic text like this

Represents text that you type.Bold text like this

Represents output that appears on the terminal screen.

Introduces or emphasizes important

•

new terms.

Identifies guide names.

•

Identifies RFC and Internet draft

•

titles.

To enter configuration mode, type the configure command:

user@host> configure

user@host> show chassis alarms

No alarms currently active

A policy term is a named structure

•

that defines match conditions and actions.

Junos OS CLI User Guide

•

RFC 1997, BGP Communities

•

Attribute

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Table 2: Text and Syntax Conventions (continued)

ExamplesDescriptionConvention

Italic text like this

Text like this

< > (angle brackets)

| (pipe symbol)

Represents variables (options for which you substitute a value) in commands or configuration statements.

Represents names of configuration statements, commands, files, and directories; configuration hierarchy levels; or labels on routing platform components.

variables.

Indicates a choice between the mutually exclusive keywords or variables on either side of the symbol. The set of choices is often enclosed in parentheses for clarity.

Configure the machine’s domain name:

[edit] root@# set system domain-name

domain-name

To configure a stub area, include

•

the stub statement at the [edit protocols ospf area area-id]

hierarchy level.

The console port is labeled

•

CONSOLE.

stub <default-metric metric>;Encloses optional keywords or

broadcast | multicast

(string1 | string2 | string3)

# (pound sign)

[ ] (square brackets)

Indention and braces ( { } )

; (semicolon)

GUI Conventions

Indicates a comment specified on the same line as the configuration statement to which it applies.

Encloses a variable for which you can substitute one or more values.

Identifies a level in the configuration hierarchy.

Identifies a leaf statement at a configuration hierarchy level.

rsvp { # Required for dynamic MPLS only

community name members [ community-ids ]

[edit] routing-options {

static {

route default {

nexthop address; retain;

}

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Table 2: Text and Syntax Conventions (continued)

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ExamplesDescriptionConvention

Bold text like this

> (bold right angle bracket)

Represents graphical user interface (GUI) items you click or select.

Separates levels in a hierarchy of menu selections.

In the Logical Interfaces box, select

•

All Interfaces.

To cancel the configuration, click

•

Cancel.

In the configuration editor hierarchy, select Protocols>Ospf.

Documentation Feedback

We encourage you to provide feedback so that we can improve our documentation. You can use either of the following methods:

Online feedback system—Click TechLibrary Feedback, on the lower right of any page on the Juniper

•

Networks TechLibrary site, and do one of the following:

Click the thumbs-up icon if the information on the page was helpful to you.

•

Click the thumbs-down icon if the information on the page was not helpful to you or if you have

•

suggestions for improvement, and use the pop-up form to provide feedback.

E-mail—Send your comments to techpubs-comments@juniper.net. Include the document or topic name,

•

URL or page number, and software version (if applicable).

Requesting Technical Support

Technical product support is available through the Juniper Networks Technical Assistance Center (JTAC). If you are a customer with an active Juniper Care or Partner Support Services support contract, or are

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covered under warranty, and need post-sales technical support, you can access our tools and resources online or open a case with JTAC.

JTAC policies—For a complete understanding of our JTAC procedures and policies, review the JTAC User

•

Guide located at https://www.juniper.net/us/en/local/pdf/resource-guides/7100059-en.pdf.

Product warranties—For product warranty information, visit https://www.juniper.net/support/warranty/.

•

JTAC hours of operation—The JTAC centers have resources available 24 hours a day, 7 days a week,

•

365 days a year.

Self-Help Online Tools and Resources

For quick and easy problem resolution, Juniper Networks has designed an online self-service portal called the Customer Support Center (CSC) that provides you with the following features:

Find CSC offerings: https://www.juniper.net/customers/support/

•

Search for known bugs: https://prsearch.juniper.net/

•

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Find product documentation: https://www.juniper.net/documentation/

•

Find solutions and answer questions using our Knowledge Base: https://kb.juniper.net/

•

Download the latest versions of software and review release notes:

•

https://www.juniper.net/customers/csc/software/

Search technical bulletins for relevant hardware and software notifications:

•

https://kb.juniper.net/InfoCenter/

Join and participate in the Juniper Networks Community Forum:

•

https://www.juniper.net/company/communities/

Create a service request online: https://myjuniper.juniper.net

•

To verify service entitlement by product serial number, use our Serial Number Entitlement (SNE) Tool:

https://entitlementsearch.juniper.net/entitlementsearch/

Creating a Service Request with JTAC

You can create a service request with JTAC on the Web or by telephone.

Visit https://myjuniper.juniper.net.

•

Call 1-888-314-JTAC (1-888-314-5822 toll-free in the USA, Canada, and Mexico).

•

For international or direct-dial options in countries without toll-free numbers, see

https://support.juniper.net/support/requesting-support/.

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CHAPTER

Overview

EX9251 System Overview | 19

EX9251 Chassis | 26

EX9251 Cooling System | 33

EX9251 Power System | 36

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EX9251 System Overview

IN THIS SECTION

EX9251 Switch Hardware Overview | 19

EX9251 Switch Models | 24

EX9251 Switch Hardware and CLI Terminology Mapping | 24

EX9251 Switch Hardware Overview

IN THIS SECTION

Software | 20

Benefits of the EX9251 Switch | 20

EX9251 Switch Models | 20

Front Panel of an EX9251 Switch | 20

Rear Panel of an EX9251 Switch | 22

Routing Engine | 22

Power Supplies | 23

Cooling System | 23

Component Redundancy | 23

Juniper Networks EX9251 Ethernet Switch is an Ethernet-optimized switch that provides carrier-class Ethernet switching. It is a fixed configuration switch with a built-in Routing Engine. It has a throughput of up to 400 gigabits per second (Gbps).

The switch has eight 10-Gigabit Ethernet ports and four rate-selectable ports that you can configure as 100-Gigabit Ethernet ports or 40-Gigabit Ethernet ports; each rate-selectable port can be configured as four 10-Gigabit Ethernet ports by using a breakout cable. The 10-Gigabit Ethernet ports support SFP+ transceivers and rate-selectable ports support QSFP28 and QSFP+ transceivers. The switch supports two power supplies and three fan trays.

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Software

Juniper Networks EX Series Ethernet Switches run Junos OS, which provides Layer 2 and Layer 3 switching, routing, and security services. The same Junos OS code base that runs on EX Series switches also runs on all Juniper Networks M Series, MX Series, and T Series routers, and SRX Series Services Gateways.

Benefits of the EX9251 Switch

Simplified network architecture—EX9251 switches deliver a simple, secure, virtualized network environment that increases business agility. They are ideal for simplifying campus, data center, and combined campus and data center network environments by collapsing network layers.

Support for Junos Fusion Enterprise—EX9251 switches support Junos Fusion Enterprise technology that enables a large number of devices deployed throughout a building to be managed as a single, logical device, thus reducing network complexity, simplifying network management, and lowering operational costs.

EX9251 Switch Models

EX9251 switch is available in two models—with AC power supply and with DC power supply. See “EX9251

Switch Models” on page 24.

Front Panel of an EX9251 Switch

Figure 1 on page 21 shows the front panel of an EX9251 switch.

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Figure 1: Front Panel of an EX9251 Switch

g022400

1016

732 4 6

1 5

1314 1112

100G, 40G, and 10G speeds and support transceivers and direct attach copper (DAC) cables.

9—1— Reset button—button to reset the switch.Rate-selectable ports—These ports can operate in

Management Ethernet port—This port connects the switch to a management device (or any other device that plugs into an Ethernet connection) for out-of-band management through an Ethernet connection. The port uses an autosensing RJ-45 connector to support 10-Mbps, 100-Mbps, or 1000-Mbps connections.

supply (BITS) external clocking port, that connects the switch to external clocking devices.

interface that you can use to install Junos OS manually. Junos OS supports USB version 1.0 and later.

1PPS and 10 MHz GPS input and output timing ports—1-pulse-per-second (PPS) connectors and 10-MHz timing connectors respectively (one input and one output), that connects the switch to external clock signal sources. The clocking ports provide the synchronized output clocks from any one of the reference clock inputs based on the clock’s priority.

10—2— SSD0 LED—indicates the status of the solid-state

drive labeled SSD0.

11—3— Alarm LED—indicates alarms.BITS ports with LEDs—Building-integrated timing

12—4— OK/Fail LED—indicates the status of the switch.USB port—USB port, that provides a removable media

13—5— Time of day (ToD) port with LED—ToD port, that

connects the switch to external timing signal sources.

Online LED—indicates the status of the switch and the operating system.

SSD1 LED—indicates the status of the solid-state drive labeled SSD1.

Offline button—button to turn the switch online or offline or to power on or power off the switch.

14—6— Console port—Console port, that connects the switch

to a system console through a serial cable with an RJ-45 connector.

15—7— 10-Gigabit Ethernet SFP+ ports—support SFP+

transceivers and direct attach copper (DAC) cables.

16—8— PTP grandmaster clock (GM/PTP) port—PTP

grandmaster clock port, that connects the switch to a timing device. Support for this port is not available in this release.

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Rear Panel of an EX9251 Switch

g022401

g022042

1 2

Figure 2 on page 22 shows the rear panel of an EX9251 switch with AC power supply. Figure 3 on page 22

shows the rear panel of an EX9251 switch with DC power supply.

Figure 2: Rear Panel of an EX9251 Switch with AC Power Supply

4—1— Fan tray LEDsProtective earthing terminal

5—2— AC power supply unitsElectrostatic discharge (ESD) point

3—Fan trays

Figure 3: Rear Panel of an EX9251 Switch with DC Power Supply

2—1— DC power supply unitsFan trays

Routing Engine

EX9251 switches have a single built-in Routing Engine. It provides switching protocol processes and software processes that control the switch’s interface, the chassis components, system management, and user access to the switch. These switching processes run on top of a kernel that interacts with the Packet Forwarding Engine. The Routing Engine is built-in on the baseboard and cannot be replaced.

It supports the following functionalities to manage the operation of the switch:

System control functions such as environmental monitoring

•

Routing Layer 2 and Layer 3 protocols

•

Communication to components such as power supplies and fan trays

•

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Transparent clocking

•

Alarm and logging functions

•

It consists of the following internal components:

High-performance 1.6-GHz Intel 8 Core X86 CPU

•

32-GB DDR4 RAM

•

2x100-GB SATA SSD

•

Power Supplies

EX9251 switches support AC power supply and DC power supply. See “Power Supplies in an EX9251

Switch” on page 36.

CAUTION: Do not mix AC and DC power supplies in the same chassis.

Cooling System

The cooling system in an EX9251 switch consists of three fan trays. The fan trays are installed on the rear panel of the chassis. Each fan tray contains one counter rotating fan. See “EX9251 Cooling System” on

page 33.

Component Redundancy

A fully configured EX9251 switch is designed such that no single point of failure can cause the entire system to fail. The following major hardware components are redundant:

Power supplies—The switch supports two power supplies. If one power supply fails in a fully configured

•

switch, the other power supply can provide full power to the switch.

Cooling system—The switch supports three fan trays. If one fan fails or the temperature of the chassis

•

rises above the temperature threshold in a fully configured switch, the speed of the remaining fans is automatically adjusted to keep the temperature within the acceptable range.

CAUTION: In a fully configured switch, all the three fan trays and the two power

supplies must be operational. In the event of any failure, the failed component must be replaced immediately.

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EX9251 Switch Models

EX9251 is available in two models—with AC power supply and with DC power supply. Table 3 on page 24 lists the models and the components included in each model.

Table 3: EX9251 Switch Models

First Junos OS ReleaseConfiguration ComponentsSwitch Models

EX9251-8X4C

EX9251-8X4C-DC

Chassis

•

Three fan trays

•

Two AC power supplies

•

Chassis

•

Three fan trays

•

Two DC power supplies

•

18.1R1

EX9251 Switch Hardware and CLI Terminology Mapping

This topic describes the hardware terms used in EX9251 switch documentation and the corresponding terms used in the Junos OS CLI. See Table 4 on page 24.

Table 4: CLI Equivalents of Terms Used in Documentation for EX9251 Switches

Hardware Item (CLI)

Item in DocumentationValue (CLI)Description (CLI)

Additional Information

Engine

Switch chassis–EX9251Chassis

Routing Engine0EX9251-RERouting

Routing Engine0EX9251CB

“Chassis Physical Specifications of an EX9251 Switch” on page 26

“EX9251 Switch Hardware Overview” on page 19

––0FPCFPC

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Table 4: CLI Equivalents of Terms Used in Documentation for EX9251 Switches (continued)

Hardware Item (CLI)

PIC (n)

Xcvr (n)

PEM (n)

Abbreviated name of the Physical Interface Card (PIC). One of the following:

4XQSFP28 PIC

•

8XSFPP PIC

•

Abbreviated name of the transceiver.

One of the following:

AC AFO 650W

•

PSU

JPSU-650W-DC-AFO

•

0-1. The value corresponds to the PIC slot number.

the number of the port in which the transceiver is installed.

n is a value in the range 0-1. The value corresponds to the power supply slot number.

Item in DocumentationValue (CLI)Description (CLI)

Optical transceiversn is a value equivalent to

AC or DC power supply

Additional Information

––n is a value in the range

Hardware Compatibility Tool page for EX9251

“Power Supplies in an EX9251 Switch” on page 36

Fan tray (n)

Fan Tray, Front to Back Airflow - AFO

Fan trayn is a value in the range 0-2. The value corresponds to the fan tray slot number.

“EX9251 Cooling System” on page 33

Table 5 on page 25 lists the spare parts and blank panels available for the switch. They must be ordered

separately.

Table 5: Spare Parts and Blank Panels

DescriptionModel Number

EX9251 chassis, spareEX9251-CHAS

EX9251 power supply slot blank panelJNP-PWR-BLNK-1

Page 26

EX9251 Chassis

IN THIS SECTION

Chassis Physical Specifications of an EX9251 Switch | 26

Field-Replaceable Units in an EX9251 Switch | 27

LEDs on the Front Panel of an EX9251 Switch | 27

Chassis Physical Specifications of an EX9251 Switch

The EX9251 switch chassis is a rigid sheet-metal structure that houses all components of the switch. EX9251 is available in two variants—with AC power supply and with DC power supply. Table 6 on page 26 summarizes the physical specifications of the EX9251 switch chassis.

Table 6: Physical Specifications of the EX9251 Switch Chassis

19 in. (48.26 cm)22.7 lb (10.3 kg)Chassis

18.5 in. (47 cm)

•

20.43 in.

•

(51.89 cm) with fan tray and power supply handles

You can mount an EX9251 switch on four posts of a 19-in. rack or an ETSI rack.

HeightDepthWidthWeightDescription

1.72 in. (4.37 cm)

1.64 in. (4.17 cm)5.78 in. (14.68 cm)1.89 in. (4.8 cm)0.29 lb (0.13 kg)Fan tray

1.58 in. (4.01 cm)14.5 in. (36.83 cm)2.23 in. (5.66 cm)2.2 lb (1 kg)AC power supply

1.67 in. (4.24 cm)14.53 in. (36.91 cm)2.23 in. (5.66 cm)2.2 lb (1 kg)DC power supply

Page 27

Field-Replaceable Units in an EX9251 Switch

Field-replaceable units (FRUs) are components that you can replace at your site. The FRUs in EX9251 switches are hot-removable and hot-insertable. You can remove and replace them without powering off the switch. The FRUs in EX9251 switches are:

Power supplies

•

Fan trays

•

Transceivers

•

NOTE: If you have a Juniper J-Care service contract, register any addition, change, or upgrade

of hardware components at

https://www.juniper.net/customers/support/tools/updateinstallbase/ . Failure to do so can

result in significant delays if you need replacement parts. This note does not apply if you replace existing components with the same type of component.

To install an AC power supply in an EX9251 switch, follow instructions in “Installing an AC Power Supply

in an EX9251 Switch” on page 128. To remove an AC power supply from an EX9251 switch, follow

instructions in “Removing an AC Power Supply from an EX9251 Switch” on page 126.

To install a DC power supply in an EX9251 switch, follow instructions in “Installing a DC Power Supply in

an EX9251 Switch” on page 131. To remove a DC power supply from an EX9251 switch, follow instructions

in “Removing a DC Power Supply from an EX9251 Switch” on page 129.

To install a fan tray in an EX9251 switch, follow instructions in “Installing a Fan Tray in an EX9251 Switch”

on page 122. To remove a fan tray from an EX9251 switch, follow instructions in “Removing a Fan Tray from an EX9251 Switch” on page 121.

To install a transceiver in an EX9251 switch, follow instructions in “Install a Transceiver” on page 108 or

“Install a QSFP28 Transceiver” on page 142. To remove a transceiver from an EX9251 switch, follow

instructions in “Remove a Transceiver” on page 135 or “Remove a QSFP28 Transceiver” on page 140.

LEDs on the Front Panel of an EX9251 Switch

The four rate-selectable ports on the front panel of an EX9251 switch has four LEDs each, which indicate the link status and activity on the port. Figure 4 on page 28 shows the LEDs on the rate-selectable ports.

Table 7 on page 28 describes the link activity LED on those ports.

Page 28

Figure 4: LEDs on the Rate-selectable Ports

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1 2 3 4

3—1— LED2LED0

4—2— LED3LED1

Table 7: Link/Activity LED on the Rate-Selectable Ports

Port Speed

Color/StateLED 10G40G100G

GreenLED 0

Amber

Off

A 100G module is plugged in, the port link is up, and there is no alarm or failure.

The interface is administratively disabled.

No 100G module is plugged in.

A 40G module is plugged in, the port link is up, and there is no alarm or failure.

The interface is administratively disabled.

No 40G module is plugged in.

Not applicableNot applicableGreenLED 1

Not applicableNot applicableAmber

A 10G module is plugged in, the port link is up, and there is no alarm or failure.

The port link is down.The port link is down.The port link is down.Red

The interface is administratively disabled.

No 10G module is plugged in.

A 10G module is plugged in, the port link is up, and there is no alarm or failure.

The port link is down.Not applicableNot applicableRed

The interface is administratively disabled.

Not applicableNot applicableOff

No 10G module is plugged in.

Page 29

Table 7: Link/Activity LED on the Rate-Selectable Ports (continued)

Port Speed

Color/StateLED 10G40G100G

Not applicableNot applicableGreenLED 2

Not applicableNot applicableAmber

Not applicableNot applicableOff

Not applicableNot applicableGreenLED 3

Not applicableNot applicableAmber

A 10G module is plugged in, the port link is up, and there is no alarm or failure.

The port link is down.Not applicableNot applicableRed

The interface is administratively disabled.

No 10G module is plugged in.

A 10G module is plugged in, the port link is up, and there is no alarm or failure.

The port link is down.Not applicableNot applicableRed

The interface is administratively disabled.

Not applicableNot applicableOff

No 10G module is plugged in.

The eight 10-Gigabit Ethernet SFP+ ports on the front panel of an EX9251 switch has one LED each, which indicate the link status and activity on the port. Figure 5 on page 30 shows the LEDs on the SFP+ ports labeled 1/0, 1/2, 1/4, and 1/6. Figure 5 on page 30 shows the LEDs on the SFP+ ports labeled 1/1, 1/3,

1/5, and 1/7. Table 8 on page 30 describes those LEDs.

Page 30

Figure 5: LEDs on the SFP+ Ports Labeled 1/0, 1/2, 1/4, and 1/6

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1 2

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1 2 3

3—1— LED on the port labeled 1/4LED on the port labeled 1/0

4—2— LED on the port labeled 1/6LED on the port labeled 1/2

Figure 6: LEDs on the SFP+ Ports Labeled 1/1, 1/3, 1/5, and 1/7

3—1— LED on the port labeled 1/5LED on the port labeled 1/1

4—2— LED on the port labeled 1/7LED on the port labeled 1/3

Table 8: Link/Activity LED on the 10-Gigabit Ethernet SFP+ Ports

State and DescriptionColor/StateLED

The port link is up and there is no alarm or failure.GreenLink activity

The port link is down.Red

The port is not enabled.Off

Figure 7 on page 31 shows the LEDs on the management port and Figure 8 on page 31 shows the LEDs

on the BITS port. Table 9 on page 31 describes the functions of the LEDs on the other ports on the front panel.

Page 31

Figure 7: LEDs on the Management Port

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1 2

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1 2

Figure 8: LEDs on the BITS Port

2—1— Link/Activity LEDSpeed LED

Table 9: Front Panel LEDs

2—1— Link LEDActivity LED

DescriptionStateColorLED

On steadilyGreenONLINE

Both Junos OS and Linux are successfully loaded on the switch.

The switch is starting Junos OS.Blinking

The switch has loaded Linux.On steadilyRed

The switch is starting Linux.Blinking

The switch is offline.Off–

The switch is functioning normally.On steadilyGreenOK/FAIL

The switch has failed.BlinkingRed

The switch is not powered on.Off–

Page 32

Table 9: Front Panel LEDs (continued)

DescriptionStateColorLED

LED on the MGMT port

On steadilyRedALM

On steadilyYellow

Critical alarm—Indicates a critical condition that can cause the switch to stop functioning. Possible causes include component removal, failure, or overheating, or any major software failure.

Warning alarm—Indicates a serious but nonfatal error condition, such as a maintenance alert or a significant increase in component temperature.

There is no alarm.Off–

SSD0 is being accessed by the switch.BlinkingGreenSSD0

SSD0 is not active or not being accessed.Off–

SSD1 is being accessed by the switch.BlinkingGreenSSD1

SSD1 is not active or not being accessed.Off–

The port and the link are active, and there is link activity.BlinkingGreenLink/Activity

The port and the link are active, but there is no link activity.On steadily

on the MGMT port

on the BITS port

the BITS port

The port is not active.Off

Link speed is 1000 Mbps.On steadilyGreenSpeed LED

Link speed is 100 Mbps.On steadilyAmber

Link speed is 10 Mbps.Off–

There is no loss (BITS is in locked state).On steadilyGreenActivity LED

There is loss of signal or loss of line.Off–

There is loss of signal or loss of line.On steadilyAmberLink LED on

There is no loss (BITS is in locked state).Off–

Page 33

EX9251 Cooling System

IN THIS SECTION

Fan Trays | 33

Airflow Direction in the EX9251 Switch Chassis | 34

Cooling System in the Power Supplies | 35

Fan Tray Status LEDs | 35

The cooling system components work together to keep all switch components within the acceptable temperature range.

The cooling system in an EX9251 switch consists of three fan trays. Under normal operating conditions, the fans in the fan trays run at a moderate speed. Temperature sensors inside the chassis monitor the temperature of the switch components. If a fan fails or the ambient temperature rises above the acceptable range, the system raises an alarm and the speed of the remaining fans is automatically adjusted to keep the temperature within the acceptable range. If the ambient maximum temperature is exceeded and the switch cannot be cooled adequately, the Routing Engine shuts down the switch.

Fan Trays

The fan trays are hot-insertable and hot-removable field-replaceable units (FRUs). The fan trays are installed on the rear panel of the chassis. Each fan tray contains one counter rotating fan. See Figure 9 on page 34 and Figure 10 on page 34.

Page 34

Figure 9: Fan Tray in an EX9251 Switch

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2 2

Figure 10: Faceplate of a Fan Tray in an EX9251 Switch

Airflow Direction in the EX9251 Switch Chassis

The switch has front-to-back (AIR OUT) airflow. The air intake to cool the chassis is through the vents on the front of the chassis. Air is pulled through the chassis towards the fan tray and hot air exhausts through the rear of the chassis. See Figure 11 on page 35.

2—1— LatchScrew

Page 35

Figure 11: Airflow Through the EX9251 Switch Chassis

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Ports

FRUs

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Cooling System in the Power Supplies

The power supplies are self-cooling units. Each power supply has its own built-in fan that cools the power supply. The power supplies are installed on the rear panel of the switch. The air exhaust for the power supplies are also located on the rear panel of the chassis.

Fan Tray Status LEDs

The LEDs indicating the state of the fan trays are located adjacent to the fan tray slots on the rear panel of the chassis (see Figure 12 on page 35).

Figure 12: Fan Tray Status LEDs

1—Fan tray status LEDs

The fan tray status LEDs are bicolor LEDs. Table 10 on page 36 describes the behavior of the fan tray status LEDs.

Page 36

Table 10: Fan Tray Status LEDs

DescriptionStateColor

Fan tray hardware initialization is complete and software initialization is pending.BlinkingGreen

Software initialization is complete and the fan is functioning normally.On

steadily

Red

steadily

Fan tray is faulty and not functioning normally.On

Fan tray is not present.Off–

EX9251 Power System

IN THIS SECTION

Power Supplies in an EX9251 Switch | 36

AC Power Cord Specifications for an EX9251 Switch | 42

Power Requirements for EX9251 Switch Components | 44

Power Supply Specifications for EX9251 Switches | 45

Power Supplies in an EX9251 Switch

IN THIS SECTION

AC Power Supply Description | 37

AC Power Supply LEDs and Other Components | 38

Page 37

DC Power Supply Description | 40

DC Power Supply LEDs and Other Components | 40

An EX9251 switch uses either AC or DC power supplies. You can install up to two power supplies in slots labeled 0 and 1 on the right side of the rear panel of the chassis. The power supply in EX9251 switches is a hot-insertable and hot-removable field-replaceable unit (FRU). You can install it without powering off the switch or disrupting the switching function.

The power supplies connect to the PEM board, which distributes the different output voltages produced by the power supplies to the switch components, depending on their voltage requirements. When both the power supplies are present, they share power almost equally within a fully populated system. If the first power supply in a redundant configuration fails or is removed, the second power supply assumes the entire electrical load without interruption. A single power supply provides the maximum configuration with full power for as long as the switch is operational. A second power supply can be installed for redundancy. The chassis is designed to support 1+1 feed redundancy.

CAUTION: Do not mix AC and DC power supplies in a switch.

NOTE: The switches are shipped with two power supplies pre-installed on the rear panel.

The power supplies are self-cooling units. Each power supply has its own built-in fan that cools the power supply.

AC Power Supply Description

Each AC power supply weighs approximately 2.2 lb (1 kg) and has a handle, an ejection lever, an AC appliance inlet, a fan, and LEDs to monitor the status of the power supply. Figure 13 on page 38 shows the power supply.

Each power supply requires a dedicated AC power feed and a dedicated customer-site circuit breaker. We recommend that you use a minimum 20 A (110 VAC) or 16 A (220 VAC) customer-site circuit breaker, or as required by local code.

Page 38

WARNING: The switch is pluggable type A equipment installed in a restricted-access

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location. It has a separate protective earthing terminal (sized for 10-32 screws) on the rear panel of the chassis in addition to the grounding pin of the power supply cord. This separate protective earthing terminal must be permanently connected to earth.

Figure 13: AC Power Supply in an EX9251 Switch

AC Power Supply LEDs and Other Components

Figure 14 on page 38 shows the LEDs and other components on an AC power supply without the AC

power cord retainer installed.

Figure 14: LEDs and Other Components on an AC Power Supply Without the AC Power Cord Retainer Installed

4—1— Fault LEDHandle

5—2— Ejector leverInput status LED

6—3— AC power cord retainer portOutput status LED

Figure 15 on page 39 shows the LEDs and other components on an AC power supply with the AC power

cord retainer installed.

Page 39

Figure 15: LEDs and Other Components on an AC Power Supply With the AC Power Cord Retainer

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Installed

4—1— Fault LEDHandle

5—2— AC power cord retainerInput status LED

6—3— Ejector leverOutput status LED

Table 11 on page 39 describes the LEDs on the AC power supply.

Table 11: AC Power Supply LEDs

DescriptionStateColorLabel

OffUnlitAC OK

On steadilyAmber! (Fault)

The power supply is disconnected from power source, or the power supply is not receiving power.

Power supply is receiving power.On steadilyGreen

Power supply output is off.OffUnlitDC OK

The power supply is sending out power correctly.On steadilyGreen

An error is detected in the power supply. Replace the power supply as soon as possible. To maintain proper airflow through the chassis, leave the power supply installed in the chassis until you are ready to replace it.

NOTE: If the AC OK LED and the DC OK LED are unlit, either the AC power cord is not installed

properly or the power supply fuse has failed. If the AC OK LED is lit and the DC OK LED is unlit, the AC power supply is installed properly, but the power supply has an internal failure.

Page 40

DC Power Supply Description

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Each DC power supply weighs approximately 2.2 lb (1 kg) and has a handle, an ejection lever, a fan, LEDs to monitor the status of the power supply, and a terminal block that provides a single DC input (–48 VDC and return) that requires a dedicated customer-site circuit breaker. We recommend that you use a dedicated customer-site circuit breaker rated for 25 A (–48 VDC) minimum, or as required by local code. If you plan to operate a DC-powered switch at less than the maximum configuration and do not provision a 25 A (–48 VDC) circuit breaker, we recommend that you provision a dedicated customer-site circuit breaker for each DC power supply rated for at least 125 percent of the continuous current that the system draws at –48 VDC.Figure 16 on page 40 shows the power supply.

WARNING: The switch is pluggable type A equipment installed in a restricted-access

location. It has a separate protective earthing terminal (sized for 10-32 screws) on the rear panel of the chassis. This separate protective earthing terminal must be permanently connected to earth.

Figure 16: DC Power Supply in an EX9251 Switch

DC Power Supply LEDs and Other Components

Figure 17 on page 41 shows the DC power supply status LEDs and other components on a DC power

supply.

Page 41

Figure 17: DC Power Supply LEDs and Other Components on a DC Power Supply

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1 2 3

3—1— Fault LEDInput status LED

2—Output status LED

CAUTION: On the DC power supply, the V+ terminals are shunted internally together,

as are the V– terminals. Terminal with the same polarity can be wired together from the same source to provide an additional current path in a higher power chassis. Do not connect the terminals to different sources.

Table 12 on page 41 describes the LEDs on the DC power supply.

Table 12: DC Power Supply LEDs

OffUnlitIN (Input)

On steadilyGreen

On steadilyAmber! (Fault)

DescriptionStateColorLabel

The power supply is disconnected from power source, or the power supply is not receiving power.

Power supply is receiving power.On steadilyGreen

Power supply output is off.OffUnlitOUT (Output)

The power supply is sending out power correctly.

Page 42

AC Power Cord Specifications for an EX9251 Switch

Each AC power supply has a single AC appliance inlet located on the faceplate that requires a dedicated AC power feed. A detachable AC power cord is supplied with the AC power supply. The coupler is type C13 as described by International Electrotechnical Commission (IEC) standard 60320. The plug end of the power cord fits into the power source outlet that is standard for your geographical location.

Table 13 on page 42 provides specifications and Figure 18 on page 43 depicts the plug on the AC power

cord for some of the countries or regions listed in Table 13 on page 42.

Table 13: AC Power Cord Specifications

Juniper Model NumberPlug StandardsElectrical SpecificationsCountry/Region

CBL-EX-PWR-C13-ARIRAM 2073 Type RA/3250 VAC, 10 A, 50 HzArgentina

Switzerland, and United Kingdom)

Japan

250 VAC, 10 A, 50 HzAustralia

250 VAC, 10 A, 50 HzChina

60 Hz

CBL-EX-PWR-C13-AUAS/NZZS 3112 Type

SAA/3

CBL-EX-PWR-C13-BRNBR 14136 Type BR/3250 VAC, 10 A, 50 HzBrazil

CBL-EX-PWR-C13-CHGB 1002-1996 Type

PRC/3

CBL-EX-PWR-C13-EUCEE (7) VII Type VIIG250 VAC, 10 A, 50 HzEurope (except Italy,

CBL-EX-PWR-C13-INIS 1293 Type IND/3250 VAC, 10 A, 50 HzIndia

CBL-EX-PWR-C13-ILSI 32/1971 Type IL/3G250 VAC, 10 A, 50 HzIsrael

CBL-EX-PWR-C13-ITCEI 23-16 Type I/3G250 VAC, 10 A, 50 HzItaly

CBL-EX-PWR-C13-JPSS-00259 Type VCTF125 VAC, 12 A, 50 Hz or

Korea

60 Hz

250 VAC, 10 A, 50 HzSouth Africa

CBL-EX-PWR-C13-KRCEE (7) VII Type VIIGK250 VAC, 10 A, 50 Hz or

CBL-EX-PWR-C13-USNEMA 5-15 Type N5-15125 VAC, 13 A, 60 HzNorth America

CBL-EX-PWR-C13-SASABS 164/1:1992 Type

ZA/13

Page 43

Table 13: AC Power Cord Specifications (continued)

Juniper Model NumberPlug StandardsElectrical SpecificationsCountry/Region

CBL-EX-PWR-C13-SZSEV 6534-2 Type 12G250 VAC, 10 A, 50 HzSwitzerland

Taiwan

Figure 18: AC Plug Types

WARNING: The AC power cord for the switch is intended for use with the switch

only and not for any other use.

WARNING:

125 VAC, 11 A and 15 A, 50 Hz

250 VAC, 10 A, 50 HzUnited Kingdom

CBL-EX-PWR-C13-TWNEMA 5-15P Type

N5-15P

CBL-EX-PWR-C13-UKBS 1363/A Type

BS89/13

Translation from Japanese: The attached power cable is only for this product. Do not use the cable for another product.

NOTE: In North America, AC power cords must not exceed 4.5 m (approximately 14.75 ft) in

length, to comply with National Electrical Code (NEC) Sections 400-8 (NFPA 75, 5-2.2) and 210-52, and Canadian Electrical Code (CEC) Section 4-010(3). You can order AC power cords that are in compliance.

Page 44

CAUTION: Ensure that power cords do not touch the switch components, block the

air exhaust and access to switch components, or drape where people could trip on it.

Power Requirements for EX9251 Switch Components

IN THIS SECTION

Power Requirements for EX9251 Switch Components | 44

Calculating System Thermal Output | 45

Use the information in this topic to determine the power requirements for your switch.

Power Requirements for EX9251 Switch Components

Table 14 on page 44 lists the power requirements for various hardware components when the switch is

operating under typical and maximum voltage conditions.

Table 14: Power Requirements for Switch Components

Power Requirement at 25°C (Watts; Typical)Component

Table 15 on page 44 lists the power requirements for a fully configured AC-powered switch operating

under typical voltage conditions.

Table 15: Power Requirements for an AC-Powered Switch at Typical Temperature (25°C)

Power Requirement at 25°C (Watts)Chassis Configuration

Power Requirement at 55°C (Watts; Maximum)

280 W240 WFully loaded switch

Power Requirement (Watts) with 90% Efficiency

266 W240 WFully configured chassis running at high activity

Page 45

Table 16 on page 45 lists the power requirements for a fully configured AC-powered switch operating

under maximum voltage conditions.

Table 16: Power Requirements for an AC-Powered Switch at Maximum Temperature (55°C)

Power Requirement Power Requirement at 55°C (Watts)Chassis Configuration

(Watts) with 90%

Efficiency

311 W280 WFully configured chassis running at high activity

Calculating System Thermal Output

After you have calculated the power consumption for your configuration, you can use that information to determine the system thermal output (BTUs per hour). To do so, multiply the power consumption in watts by 3.41.

For example, in Table 15 on page 44, we calculated the power consumption for a fully configured chassis running at high activity at 25°C typical temperature to be 240 W. Using that information, we can calculate the system thermal output for the configuration:

Power consumption in watts * 3.41 = system thermal output in BTU/hr 240 W * 3.41 = 818.4 BTU/hr

Power Supply Specifications for EX9251 Switches

Table 17 on page 45 lists the AC power system electrical specifications.

Table 17: AC Power System Electrical Specifications

SpecificationsItem

Operating range: 100 through 240 VACAC input voltage

50–60 Hz (nominal)AC input line frequency

AC system current rating

3.2 A @ 100 VAC

•

1.37 A @ 240 VAC

•

312 WAC system input power

Table 18 on page 46 lists the AC power supply electrical specifications.

Page 46

Table 18: AC Power Supply Electrical Specifications

SpecificationsItem

650 WMaximum output power

AC input voltage

AC input current rating

Operating range:

100 through 127 VAC

•

200 through 240 VAC

•

50–60 Hz (nominal)AC input line frequency

7.8 A @ 100 VAC

•

3.8 A @ 240 VAC

•

Table 19 on page 46 lists the DC power system electrical specifications.

Table 19: DC Power System Electrical Specifications

SpecificationsItem

Operating range: –44 through –72 VDCDC input voltage

20 A@ –44 VDC (maximum)DC system input current rating

DC system input power

331 W

•

7.75 A @ –44 VDC

•

Table 20 on page 46 lists the DC power supply electrical specifications.

Table 20: DC Power Supply Electrical Specifications

SpecificationsItem

650 WMaximum output power

DC input voltage

Minimum: –44 VDC

•

Nominal: –48 VDC, –60 VDC

•

Operating range: –44 to –72 VDC

•

20 A @ –44 VDCDC input current rating

Page 47

CHAPTER

Site Planning, Preparation, and

Specifications

Site Preparation Checklist for an EX9251 Switch | 48

EX9251 Site Guidelines and Requirements | 49

EX9251 Network Cable and Transceiver Planning | 60

EX9251 Management Cable Specifications and Pinouts | 68

Page 48

Site Preparation Checklist for an EX9251 Switch

The checklist in Table 21 on page 48 summarizes the tasks you need to perform to prepare a site for installing an EX9251 switch.

Table 21: Site Preparation Checklist

Performed byFor More InformationItem or Task

Environment

Date

Verify that environmental factors such as temperature and humidity do not exceed switch tolerances.

Power

Measure distance between external power sources and switch installation site.

Calculate the power consumption and requirements.

“Environmental Requirements and Specifications for EX Series Switches” on page 49

“Power Supply Specifications for EX9251 Switches” on page 45

“Power Requirements for EX9251 Switch Components” on page 44

“Calculating the Fiber-Optic Cable Power Budget for EX Series Devices” on page 66

“Calculating the Fiber-Optic Cable Power Margin for EX Series Devices” on page 66

Rack or Cabinet

Select the type of rack or cabinet and verify that it meets the minimum requirements for the installation of the switch.

Plan rack or cabinet location, ensuring the required space clearances.

Secure the rack or cabinet to the floor and building structure.

“Rack and Cabinet Requirements for EX9251 Switches” on page 57

“Clearance Requirements for Airflow and Hardware Maintenance for EX9251 Switches” on page 56

Page 49

Table 21: Site Preparation Checklist (continued)

Cables

Performed byFor More InformationItem or Task

Date

Plan the cable routing and management.

Acquire cables and connectors:

Determine the number of cables

•

needed based on your planned configuration.

Ensure that the distance between

•

hardware components to be connected allows for cable lengths to be within the specified maximum limits.

“Management Cable Specifications” on page 69

“Specifications of Cables and Wires That Connect to Ports on the Front Panel in an EX9251 Switch” on page 69

EX9251 Site Guidelines and Requirements

IN THIS SECTION

Environmental Requirements and Specifications for EX Series Switches | 49

General Site Guidelines | 54

Site Electrical Wiring Guidelines | 55

Clearance Requirements for Airflow and Hardware Maintenance for EX9251 Switches | 56

Rack and Cabinet Requirements for EX9251 Switches | 57

Environmental Requirements and Specifications for EX Series Switches

The switch must be installed in a rack or cabinet housed in a dry, clean, well-ventilated, and temperature-controlled environment.

Page 50

Ensure that these environmental guidelines are followed:

The site must be as dust-free as possible, because dust can clog air intake vents and filters, reducing the

•

efficiency of the switch cooling system.

Maintain ambient airflow for normal switch operation. If the airflow is blocked or restricted, or if the

•

intake air is too warm, the switch might overheat, leading to the switch temperature monitor shutting down the switch to protect the hardware components.

Table 22 on page 50 provides the required environmental conditions for normal switch operation.

Table 22: EX Series Switch Environmental Tolerances

Environment Tolerance

Switch or device SeismicTemperatureRelative HumidityAltitude

EX2200-C

EX2200 (except EX2200-C switches)

EX2300-C

No performance degradation up to 5,000 feet (1524 meters)

No performance degradation up to 10,000 feet (3048 meters)

No performance degradation up to 5,000 feet (1524 meters)

Normal operation ensured in the relative humidity range 10% through 85% (noncondensing)

Normal operation ensured in the temperature range 32° F (0° C) through 104°

F (40° C) at altitudes up to

5,000 ft (1,524 m).

For information about extended temperature SFP transceivers supported on EX2200 switches, see

Pluggable Transceivers

Supported on EX2200 Switches.

Normal operation ensured in the temperature range 32° F (0° C) through 113°

F (45° C)

Normal operation ensured in the temperature range 32° F (0° C) through 104°

F (40° C)

Complies with Zone 4 earthquake requirements as per GR-63, Issue 4.

EX2300 (except EX2300-C switches)

No performance degradation up to 13,000 feet (3962 meters) at 104° F (40° C) as per GR-63

Normal operation ensured in the relative humidity range 10% through 85% (noncondensing)

Normal operation ensured in the temperature range 32° F (0° C) through 113°

F (45° C)

Complies with Zone 4 earthquake requirements as per GR-63, Issue 4.

Page 51

Table 22: EX Series Switch Environmental Tolerances (continued)

Environment Tolerance

Switch or device SeismicTemperatureRelative HumidityAltitude

EX3200

EX3300

EX3400

EX4200

EX4300

The maximum thermal output for EX4300-48T is 423 BTU/hour and for EX4300-48P is 5844 BTU/hour.

No performance degradation up to 10,000 feet (3048 meters)

EX4300 switches except the EX4300-48MP model— No performance degradation up to 10,000 feet (3048 meters)

EX4300-48MP model— No performance degradation up to 6,000 feet (1829 meters)

Normal operation ensured in the relative humidity range 10% through 85% (noncondensing)

EX4300 switches except the EX4300-48MP model— Normal operation ensured in the relative humidity range 10% through 85% (noncondensing)

EX4300-48MP model— Normal operation ensured in the relative humidity range 5% through 90% (noncondensing)

Normal operation ensured in the temperature range 32° F (0° C) through 113°

F (45° C)

Normal operation ensured in the temperature range 32° F (0° C) through 113°

F (45° C)

Normal operation ensured in the temperature range 32° F (0° C) through 113°

F (45° C)

Normal operation ensured in the temperature range 32° F (0° C) through 113°

F (45° C)

Normal operation ensured in the temperature range 32° F (0° C) through 113°

F (45° C)

Complies with Zone 4 earthquake requirements as per GR-63, Issue 4.

EX4500

No performance degradation up to 10,000 feet (3048 meters)

Normal operation ensured in the relative humidity range 10% through 85% (noncondensing)

Normal operation ensured in the temperature range 32° F (0° C) through 113°

F (45° C)

Complies with Zone 4 earthquake requirements as per GR-63, Issue 4.

Page 52

Table 22: EX Series Switch Environmental Tolerances (continued)

Environment Tolerance

Switch or device SeismicTemperatureRelative HumidityAltitude

EX4550

EX4600

No performance degradation up to 10,000 feet (3048 meters)

No performance degradation to 6,562 feet (2000 meters)

Normal operation ensured in the relative humidity range 10% through 85% (noncondensing)

Normal operation ensured in the relative humidity range 5% through 90%, noncondensing

Short-term operation

•

ensured in the relative humidity range 5% through 93%, noncondensing

NOTE: As defined in

NEBS GR-63-CORE, Issue 4, short-term events can be up to 96 hours in duration but not more than 15 days per year.

EX4550-32F switches—

•

Normal operation ensured in the temperature range 32° F (0° C) through 113° F (45° C)

EX4550-32T switches—

•

Normal operation is ensured in the temperature range 32° F through 104° F (40° C)

Normal operation

•

ensured in the temperature range 32° F (0° C) through 113° F (45° C)

Nonoperating storage

•

temperature in shipping container: – 40° F (–40° C) through 158° F (70° C)

Complies with Zone 4 earthquake requirements as per GR-63, Issue 4.

Complies with Zone 4 earthquake requirements per NEBS GR-63-CORE, Issue 4.

EX4650

EX6210

No performance degradation to 6,000 feet (1829 meters)

No performance degradation up to 10,000 feet (3048 meters)

Normal operation ensured in the relative humidity range 10% through 85% (condensing)

Normal operation ensured in the relative humidity range 10% through 85% (noncondensing)

Normal operation is ensured in the temperature range 32° F (0° C) through 104°

F (40° C)

Normal operation is ensured in the temperature range 32° F (0° C) through 104°

F (40° C)

Complies with Zone 4 earthquake requirements as per GR-63, Issue 4.

Page 53

Table 22: EX Series Switch Environmental Tolerances (continued)

Environment Tolerance

Switch or device SeismicTemperatureRelative HumidityAltitude

EX8208

EX8216

EX9204

EX9208

No performance degradation up to 10,000 feet (3048 meters)

Normal operation ensured in the relative humidity range 10% through 85% (noncondensing)

Normal operation ensured in the relative humidity range 5% through 90% (noncondensing)

Normal operation is ensured in the temperature range 32° F (0° C) through 104°

F (40° C)

Normal operation is ensured in the temperature range 32° F (0° C) through 104°

F (40° C)

Normal operation is ensured in the temperature range 32° F (0° C) through 104°

F (40° C)

Nonoperating storage temperature in shipping container: – 40° F (–40° C) to 158° F (70° C)

Normal operation is ensured in the temperature range 32° F (0° C) through 104°

F (40° C)

Complies with Zone 4 earthquake requirements as per GR-63, Issue 4.

Complies with Zone 4 earthquake requirements as per GR-63.

EX9214

No performance degradation up to 10,000 feet (3048 meters)

Normal operation ensured in the relative humidity range 5% through 90% (noncondensing)

Nonoperating storage temperature in shipping container: – 40° F (–40° C) to 158° F (70° C)

Normal operation is ensured in the temperature range 32° F (0° C) through 104°

F (40° C)

Nonoperating storage temperature in shipping container: – 40° F (–40° C) through 158° F (70° C)

Complies with Zone 4 earthquake requirements as per GR-63.

Page 54

Table 22: EX Series Switch Environmental Tolerances (continued)

Environment Tolerance

Switch or device SeismicTemperatureRelative HumidityAltitude

EX9251

The maximum thermal output is 1705 BTU/hour (500 W).

XRE200

No performance degradation up to 10,000 ft (3048 m)

No performance degradation up to 10,000 feet (3048 meters)

Normal operation ensured in relative humidity range of 5% to 90%, noncondensing

Normal operation ensured in the relative humidity range 10% through 85% (noncondensing)

Normal operation ensured in temperature range of 32°

F (0° C) to 104° F (40° C)

Nonoperating storage temperature in shipping container: – 40° F (–40° C) to 158° F (70° C)

Normal operation ensured in the temperature range 41° F (5° C) through 104°

F (40° C)

Complies with Telcordia Technologies Zone 4 earthquake requirements

Complies with Zone 4 earthquake requirements as per GR-63, Issue 4.

NOTE: Install EX Series switches only in restricted areas, such as dedicated equipment rooms

and equipment closets, in accordance with Articles 110– 16, 110– 17, and 110– 18 of the National Electrical Code, ANSI/NFPA 70.

General Site Guidelines

Efficient device operation requires proper site planning and maintenance and proper layout of the equipment, rack or cabinet, and wiring closet.

To plan and create an acceptable operating environment for your device and prevent environmentally caused equipment failures:

Keep the area around the chassis free from dust and conductive material, such as metal flakes.

•

Follow prescribed airflow guidelines to ensure that the cooling system functions properly and that

•

exhaust from other equipment does not blow into the intake vents of the device.

Follow the prescribed electrostatic discharge (ESD) prevention procedures to prevent damaging the

•

equipment. Static discharge can cause components to fail completely or intermittently over time.

Install the device in a secure area, so that only authorized personnel can access the device.

•

Page 55

Site Electrical Wiring Guidelines

Table 23 on page 55 describes the factors you must consider while planning the electrical wiring at your

site.

WARNING: You must provide a properly grounded and shielded environment and use

electrical surge-suppression devices.

Avertissement Vous devez établir un environnement protégé et convenablement mis à la terre et utiliser des dispositifs de parasurtension.

Table 23: Site Electrical Wiring Guidelines

Site Wiring Factor

Guidelines

Signaling limitations

Radio frequency interference

Electromagnetic compatibility

If your site experiences any of the following problems, consult experts in electrical surge suppression and shielding:

Improperly installed wires cause radio frequency interference (RFI).

•

Damage from lightning strikes occurs when wires exceed recommended distances or pass between

•

buildings.

Electromagnetic pulses (EMPs) caused by lightning damage unshielded conductors and electronic

•

devices.

To reduce or eliminate RFI from your site wiring, do the following:

Use a twisted-pair cable with a good distribution of grounding conductors.

•

If you must exceed the recommended distances, use a high-quality twisted-pair cable with one

•

ground conductor for each data signal when applicable.

If your site is susceptible to problems with electromagnetic compatibility (EMC), particularly from lightning or radio transmitters, seek expert advice.

Some of the problems caused by strong sources of electromagnetic interference (EMI) are:

Destruction of the signal drivers and receivers in the device

•

Electrical hazards as a result of power surges conducted over the lines into the equipment

•

Page 56

Clearance Requirements for Airflow and Hardware Maintenance for EX9251

g022410

Ports

FRUs

Switches

When planning the site for installing an EX9251 switch, you must ensure sufficient clearance around the switch.

Follow these clearance requirements:

For the cooling system to function properly, the airflow around the chassis must be unrestricted. See

•

Figure 19 on page 56 for reference.

Figure 19: Airflow Through the EX9251 Switch Chassis

If you are mounting the switch on a rack or cabinet along with other equipment, ensure that the exhaust

•

from other equipment does not blow into the intake vents of the chassis.

Leave at least 6 in. (15.2 cm) clearance in front of and behind the chassis for airflow.

•

Leave at least 6 in. (15.2 cm) clearance on the left of the chassis for installing the grounding lug.

•

Leave at least 24 in. (61 cm) clearance in front of and behind the switch for service personnel to remove

•

and install hardware components. NEBS GR-63 recommends that you allow at least 30 in. (76.2 cm) in front of the rack or cabinet and 24 in. (61 cm) behind the rack or cabinet. See Figure 20 on page 57.

Page 57

Figure 20: Clearance Requirements for Airflow and Hardware Maintenance for an EX9251 Switch Chassis

g022411

18.99 in.

(4 8 .23 cm)

Clea ran c e requi red

for main t enan c e

24 in. ( 6 1 cm)

20 .41 in. ( 51.84 cm)

FRUsPorts

18.99 in.

(4 8.23 cm)

Clea ran c e requi red

for main t enan c e

24 in. ( 6 1 cm)

Rack and Cabinet Requirements for EX9251 Switches

You can mount an EX9251 switch on four-posts of a 19-in rack or an ETSI rack or in a cabinet that contains a 19-in. rack or an ETSI rack.

Rack requirements consist of:

Rack type

•

Mounting bracket hole spacing

•

Rack size and strength

•

Rack connection to the building structure

•

Table 24 on page 57 provides the rack requirements and specifications.

Table 24: Rack Requirements and Specifications

GuidelinesRack Requirement

Rack type

You can mount the device on a rack that provides bracket holes or hole patterns spaced at 1 U (1.75 in. or 4.45 cm) increments and meets the size and strength requirements to support the weight.

A U is the standard rack unit defined by the Electronic Components Industry Association (http://www.ecianow.org).

Page 58

Table 24: Rack Requirements and Specifications (continued)

GuidelinesRack Requirement

Mounting bracket hole spacing

Rack size and strength

Rack connection to building structure

The holes in the mounting brackets are spaced at 1 U (1.75 in. or 4.45 cm), so that the device can be mounted in any rack that provides holes spaced at that distance.

Ensure that the rack complies with the size and strength standards of a 19-in.

•

rack as defined by the Electronic Components Industry Association (http://www.ecianow.org) or with the size and strength standards of an ETSI rack as defined in the European Telecommunications Standards Institute (ETS 300 119) published by the European Telecommunications Standards Institute (ETSI).

Ensure that the rack rails are spaced widely enough to accommodate the

•

external dimensions of the device chassis. The outer edges of the front-mounting brackets extend the width of the chassis to 19 in. (48.2 cm).

The rack must be strong enough to support the weight of the device.

•

Ensure that the spacing of rails and adjacent racks provides for proper clearance

•

around the device and rack.

Secure the rack to the building structure.

•

If earthquakes are a possibility in your geographical area, secure the rack to the

•

floor.

Secure the rack to the ceiling brackets as well as wall or floor brackets for

•

maximum stability.

Cabinet requirements consist of:

Cabinet size

•

Clearance requirements

•

Cabinet airflow requirements

•

Table 25 on page 59 provides the cabinet requirements and specifications.

Page 59

Table 25: Cabinet Requirements and Specifications

Cabinet Requirement

Guidelines

Cabinet size

Cabinet clearance

Cabinet airflow requirements

You can mount the device in a cabinet that contains a 19-in. rack as defined by the Electronic

•

Components Industry Association (http://www.ecianow.org) or an ETSI rack as defined in the European Telecommunications Standards Institute (ETS 300 119) published by the European Telecommunications Standards Institute (ETSI).

The minimum cabinet size must be able to accommodate the maximum external dimensions

•

of the device.

The minimum total clearance inside the cabinet is 30 in. (76.2 cm) between the inside of the front door and the inside of the rear door.

When you mount the device in a cabinet, ensure that ventilation through the cabinet is sufficient to prevent overheating.

Ensure adequate cool air supply to dissipate the thermal output of the device or devices.

•

Ensure that the hot air exhaust of the chassis exits the cabinet without recirculating into

•

the device. An open cabinet (without a top or doors) that employs hot air exhaust extraction from the top ensures the best airflow through the chassis. If the cabinet contains a top or doors, perforations in these elements assist with removing the hot air exhaust.

Install the device in the cabinet in a way that maximizes the open space on the side of the

•

chassis that has the hot air exhaust.

Route and dress all cables to minimize the blockage of airflow to and from the chassis.

•

Ensure that the spacing of rails and adjacent cabinets is such that there is proper clearance

•

around the device and cabinet.

A cabinet larger than the minimum required provides better airflow and reduces the chance

•

of overheating.

SEE ALSO

Rack-Mounting and Cabinet-Mounting Warnings | 179

Page 60

EX9251 Network Cable and Transceiver Planning

IN THIS SECTION

Pluggable Transceivers Supported on EX9251 Switches | 60

SFP+ Direct Attach Copper Cables for EX Series Switches | 61

QSFP+ Direct Attach Copper Cables for EX Series Switches | 63

Understanding EX Series Switches Fiber-Optic Cable Signal Loss, Attenuation, and Dispersion | 64

Calculating the Fiber-Optic Cable Power Budget for EX Series Devices | 66

Calculating the Fiber-Optic Cable Power Margin for EX Series Devices | 66

Pluggable Transceivers Supported on EX9251 Switches

The network ports on the front panel in EX9251 switches support transceivers. You can find the list of transceivers supported on EX9251 switches and information about those transceivers in the Hardware

Compatibility Tool page for EX9251.

NOTE: We recommend that you use only optical transceivers and optical connectors purchased

from Juniper Networks with your Juniper Networks device.

CAUTION: If you face a problem running a Juniper Networks device that uses a

third-party optic or cable, the Juniper Networks Technical Assistance Center (JTAC) can help you diagnose the source of the problem. Your JTAC engineer might recommend that you check the third-party optic or cable and potentially replace it with an equivalent Juniper Networks optic or cable that is qualified for the device.

The Gigabit Ethernet transceivers installed in EX9251 switches support digital optical monitoring (DOM). You can view the diagnostic details for these transceivers by issuing the operational mode CLI command show interfaces diagnostics optics.

SEE ALSO

Page 61

Install a Transceiver | 108

Install a QSFP28 Transceiver | 142

Remove a Transceiver | 135

Remove a QSFP28 Transceiver | 140 EX9251 Switch Hardware Overview | 19

SFP+ Direct Attach Copper Cables for EX Series Switches

IN THIS SECTION

Cable Specifications | 62

List of DAC Cables Supported on EX Series Switches | 62

Standards Supported by These Cables | 63

Small form-factor pluggable plus transceiver (SFP+) direct attach copper (DAC) cables, also known as Twinax cables, are suitable for in-rack connections between servers and switches. They are suitable for short distances, making them ideal for highly cost-effective networking connectivity within a rack and between adjacent racks.

NOTE: We recommend that you use only SFP+ DAC cables purchased from Juniper Networks

with your Juniper Networks device.

CAUTION: If you face a problem running a Juniper Networks device that uses a

Page 62

Cable Specifications

EX Series switches support SFP+ passive DAC cables. The passive Twinax cable is a straight cable with no active electronic components. EX Series switches support 1 m, 3 m, 5 m, and 7 m long SFP+ passive DAC cables. See Figure 21 on page 62.

Figure 21: SFP+ Direct Attach Copper Cables for EX Series Switches

The cables are hot-removable and hot-insertable: You can remove and replace them without powering off the switch or disrupting switch functions. A cable comprises a low-voltage cable assembly that connects directly into two 10-Gigabit Ethernet ports, one at each end of the cable. The cables use high-performance integrated duplex serial data links for bidirectional communication and are designed for data rates of up to 10 Gbps.

List of DAC Cables Supported on EX Series Switches

For the list of DAC cables supported on EX Series switches and the specifications of these cables, see:

EX2300—Hardware Compatibility Tool page for EX2300

•

EX3200—Hardware Compatibility Tool page for EX3200

•

EX3300—Hardware Compatibility Tool page for EX3300

•

EX3400—Hardware Compatibility Tool page for EX3400

•

EX4200—Hardware Compatibility Tool page for EX4200

•

EX4300—Hardware Compatibility Tool page for EX4300

•

EX4500—Hardware Compatibility Tool page for EX4500

•

EX4550—Hardware Compatibility Tool page for EX4550

•

EX4600—Hardware Compatibility Tool page for EX4600

•

EX8208—Hardware Compatibility Tool page for EX8208

•

EX8216—Hardware Compatibility Tool page for EX8216

•

EX9251—Hardware Compatibility Tool page for EX9251

•

EX9253—Hardware Compatibility Tool page for EX9253

•

Page 63

Standards Supported by These Cables

The cables comply with the following standards:

SFP mechanical standard SFF-843— see ftp://ftp.seagate.com/sff/SFF-8431.PDF.

•

Electrical interface standard SFF-8432— see ftp://ftp.seagate.com/sff/SFF-8432.PDF.

•

SFP+ Multi-Source Alliance (MSA) standards

•

QSFP+ Direct Attach Copper Cables for EX Series Switches

IN THIS SECTION

Cable Specifications | 64

DAC Cables Supported on EX3400, EX4300, EX4550, EX4600, EX9251, and EX9253 Switches | 64

Quad small form-factor pluggable plus (QSFP+) direct attach copper (DAC) cables are suitable for in-rack connections between QSFP+ ports on EX3400, EX4300, EX4550, EX4600, EX9251, and EX9253 switches. They are suitable for short distances, making them ideal for highly cost-effective networking connectivity within a rack and between adjacent racks.

NOTE: We recommend that you use only QSFP+ DAC cables purchased from Juniper Networks

with your Juniper Networks device.

CAUTION: If you face a problem running a Juniper Networks device that uses a

Page 64

Cable Specifications

QSFP+ passive DAC cables are hot-removable and hot-insertable. A cable consists of a cable assembly that connects directly into two QSFP+ modules, one at each end of the cable. The cables use integrated duplex serial data links for bidirectional communication and are designed for data rates up to 40 Gbps. Passive DAC cables have no signal amplification built into the cable assembly. See Figure 22 on page 64.

Figure 22: QSFP+ Direct Attach Copper Cables

DAC Cables Supported on EX3400, EX4300, EX4550, EX4600, EX9251, and EX9253 Switches

For the list of DAC cables supported on EX3400, EX4300, EX4550, EX4600, EX9251, and EX9253 switches and the specifications of these cables, see:

EX3400—Hardware Compatibility Tool page for EX3400

•

EX4300—Hardware Compatibility Tool page for EX4300

•

EX4550—Hardware Compatibility Tool page for EX4550

•

EX4600—Hardware Compatibility Tool page for EX4600

•

EX9251—Hardware Compatibility Tool page for EX9251

•

EX9253—Hardware Compatibility Tool page for EX9253

•

Understanding EX Series Switches Fiber-Optic Cable Signal Loss, Attenuation, and Dispersion

IN THIS SECTION

Signal Loss in Multimode and Single-Mode Fiber-Optic Cable | 65

Attenuation and Dispersion in Fiber-Optic Cable | 65

Page 65

To determine the power budget and power margin needed for fiber-optic connections, you need to understand how signal loss, attenuation, and dispersion affect transmission. EX Series switches use various types of network cable, including multimode and single-mode fiber-optic cable.

Signal Loss in Multimode and Single-Mode Fiber-Optic Cable

Multimode fiber is large enough in diameter to allow rays of light to reflect internally (bounce off the walls of the fiber). Interfaces with multimode optics typically use LEDs as light sources. However, LEDs are not coherent light sources. They spray varying wavelengths of light into the multimode fiber, which reflects the light at different angles. Light rays travel in jagged lines through a multimode fiber, causing signal dispersion. When light traveling in the fiber core radiates into the fiber cladding (layers of lower refractive index material in close contact with a core material of higher refractive index), higher-order mode loss (HOL) occurs. Together, these factors reduce the transmission distance of multimode fiber compared to that of single-mode fiber.

Single-mode fiber is so small in diameter that rays of light reflect internally through one layer only. Interfaces with single-mode optics use lasers as light sources. Lasers generate a single wavelength of light, which travels in a straight line through the single-mode fiber. Compared to multimode fiber, single-mode fiber has a higher bandwidth and can carry signals for longer distances. It is consequently more expensive.

Exceeding the maximum transmission distances can result in significant signal loss, which causes unreliable transmission.

Attenuation and Dispersion in Fiber-Optic Cable

An optical data link functions correctly provided that modulated light reaching the receiver has enough power to be demodulated correctly. Attenuation is the reduction in strength of the light signal during transmission. Passive media components such as cables, cable splices, and connectors cause attenuation. Although attenuation is significantly lower for optical fiber than for other media, it still occurs in both multimode and single-mode transmission. An efficient optical data link must transmit enough light to overcome attenuation.

Dispersion is the spreading of the signal over time. The following two types of dispersion can affect signal transmission through an optical data link:

Chromatic dispersion, which is the spreading of the signal over time caused by the different speeds of

•

light rays.

Modal dispersion, which is the spreading of the signal over time caused by the different propagation

•

modes in the fiber.

For multimode transmission, modal dispersion, rather than chromatic dispersion or attenuation, usually limits the maximum bit rate and link length. For single-mode transmission, modal dispersion is not a factor. However, at higher bit rates and over longer distances, chromatic dispersion limits the maximum link length.

Page 66

An efficient optical data link must have enough light to exceed the minimum power that the receiver requires to operate within its specifications. In addition, the total dispersion must be within the limits specified for the type of link in Telcordia Technologies document GR-253-CORE (Section 4.3) and International Telecommunications Union (ITU) document G.957.

When chromatic dispersion is at the maximum allowed, its effect can be considered as a power penalty in the power budget. The optical power budget must allow for the sum of component attenuation, power penalties (including those from dispersion), and a safety margin for unexpected losses.

Calculating the Fiber-Optic Cable Power Budget for EX Series Devices

To ensure that fiber-optic connections have sufficient power for correct operation, calculate the link's power budget when planning fiber-optic cable layout and distances to ensure that fiber-optic connections have sufficient power for correct operation. The power budget is the maximum amount of power the link can transmit. When you calculate the power budget, you use a worst-case analysis to provide a margin of error, even though all the parts of an actual system do not operate at the worst-case levels.

To calculate the worst-case estimate for fiber-optic cable power budget (PB) for the link:

1. Determine values for the link's minimum transmitter power (PT) and minimum receiver sensitivity (PR). For example, here, (PT) and (PR) are measured in decibels, and decibels are referred to one milliwatt (dBm).

PT= – 15 dBm

PR= – 28 dBm

NOTE: See the specifications for your transmitter and receiver to find the minimum transmitter

power and minimum receiver sensitivity.

2. Calculate the power budget (PB) by subtracting (PR) from (PT):

– 15 dBm – (–28 dBm) = 13 dBm

Calculating the Fiber-Optic Cable Power Margin for EX Series Devices

Calculate the link's power margin when planning fiber-optic cable layout and distances to ensure that fiber-optic connections have sufficient signal power to overcome system losses and still satisfy the minimum

Page 67

input requirements of the receiver for the required performance level. The power margin (PM) is the amount of power available after attenuation or link loss (LL) has been subtracted from the power budget (PB).

When you calculate the power margin, you use a worst-case analysis to provide a margin of error, even though all the parts of an actual system do not operate at worst-case levels. A power margin (PM) greater

than zero indicates that the power budget is sufficient to operate the receiver and that it does not exceed the maximum receiver input power. This means the link will work. A (PM) that is zero or negative indicates

insufficient power to operate the receiver. See the specification for your receiver to find the maximum receiver input power.

Before calculating the power margin:

Calculate the power budget (see “Calculating the Fiber-Optic Cable Power Budget for EX Series Devices”

•

on page 66).

To calculate the worst-case estimate for the power margin (PM) for the link:

1. Determine the maximum value for link loss (LL) by adding estimated values for applicable link-loss factors—for example, use the sample values for various factors as provided in Table 26 on page 67 (here, the link is 2 km long and multimode, and the (PB) is 13 dBm):

Table 26: Estimated Values for Factors Causing Link Loss

Higher-order mode losses (HOL)

Modal and chromatic dispersion

Multimode—0.5 dBm

•

Single mode—None

•

Multimode—None, if product of

•

bandwidth and distance is less than 500 MHz/km

Single mode—None

•

0.5 dBmConnector

0.5 dBmSplice

Sample (LL) Calculation ValuesEstimated Link-Loss ValueLink-Loss Factor

0.5 dBm

•

0 dBm

•

0 dBm

•

0 dBm

•

This example assumes 5 connectors. Loss for 5 connectors:

(5) * (0.5 dBm) = 2.5 dBm

This example assumes 2 splices. Loss for two splices:

(2) * (0.5 dBm) = 1 dBm

Fiber attenuation

Multimode—1 dBm/km

•

Single mode—0.5 dBm/km

•

This example assumes the link is 2 km long. Fiber attenuation for 2 km:

(2 km) * (1.0 dBm/km) = 2 dBm

•

(2 km) * (0.5 dBm/km) = 1 dBm

•

Page 68

Table 26: Estimated Values for Factors Causing Link Loss (continued)

NOTE: For information about the actual amount of signal loss caused by equipment and

other factors, see your vendor documentation for that equipment.

2. Calculate the (PM) by subtracting (LL) from (PB):

Sample (LL) Calculation ValuesEstimated Link-Loss ValueLink-Loss Factor

1 dBm1 dBmClock Recovery Module (CRM)

PB– LL = P

(13 dBm) – (0.5 dBm [HOL]) – ((5) * (0.5 dBm)) – ((2) * (0.5 dBm)) – ((2 km) * (1.0 dBm/km)) – (1 dB [CRM]) = P

13 dBm – 0.5 dBm – 2.5 dBm – 1 dBm – 2 dBm – 1 dBm = P

PM= 6 dBm

The calculated power margin is greater than zero, indicating that the link has sufficient power for transmission. Also, the power margin value does not exceed the maximum receiver input power. Refer to the specification for your receiver to find the maximum receiver input power.

EX9251 Management Cable Specifications and Pinouts

IN THIS SECTION

Management Cable Specifications | 69

Specifications of Cables and Wires That Connect to Ports on the Front Panel in an EX9251 Switch | 69

Grounding Cable and Lug Specifications for EX9251 Switches | 70

USB Port Specifications for an EX Series Switch | 71

Console Port Connector Pinout Information for an EX9251 Switch | 72

RJ-45 to DB-9 Serial Port Adapter Pinout Information | 73

RJ-45 Management Port Connector Pinout Information | 73

Page 69

Management Cable Specifications

Table 27 on page 69 lists the specifications for the cables that connect the console and management ports

to management devices.

Table 27: Specifications of Cables to Connect to Management Devices

Additional InformationReceptacleCable SpecificationsPorts

RJ-45 console port

Management Ethernet port

Mini-USB Type-B console port

RJ-45CAT5e UTP (unshielded

twisted pair) cable

RJ-45Ethernet cable with an

RJ-45 connector

Mini-USBMini-USB cable with standard-A and Mini-USB Type-B (5-pin) connector

“Connect a Device to a Management Console Using an RJ-45 Connector” on page 104

“Connect a Device to a Network for Out-of-Band Management” on page 103

Specifications of Cables and Wires That Connect to Ports on the Front Panel in an EX9251 Switch

Table 28 on page 69 lists the specifications for the cables that connect to management port, console port,

and auxiliary port.

Table 28: Cable and Wire Specifications for Ports on the Front Panel

RS-232 (EIA-232) serial cableConsole or auxiliary port

Management Ethernet port

Category 5 cable or equivalent suitable for 100Base-T operation

connectors

Page 70

Grounding Cable and Lug Specifications for EX9251 Switches

IN THIS SECTION

Grounding Points Specifications for an EX9251 Switch | 70

Grounding Cable Specifications for an EX9251 Switch | 71

Grounding Lug Specifications for an EX9251 Switch | 71

To ensure proper operation and to meet safety and electromagnetic interference (EMI) requirements, you must connect an EX9251 switch to earth ground before you connect power to the switch. You must use the protective earthing terminal on the rear panel of the switch chassis to connect the switch to earth ground.

WARNING: The switch is installed in a restricted-access location. It has a separate

protective earthing terminal on the rear panel of the chassis that must be permanently connected to earth ground to adequately ground the chassis and protect the operator from electrical hazards.

CAUTION: Before switch installation begins, ensure that a licensed electrician has

attached an appropriate grounding lug to the grounding cable that you supply. Using a grounding cable with an incorrectly attached lug can damage the switch.

Grounding Points Specifications for an EX9251 Switch

Two threaded holes are provided on the rear left side of the chassis for connecting the switch to earth ground. The grounding points fit 10–32 screws and are spaced at 0.63 in. (16 mm) centers.

NOTE: Additional grounding is provided to an AC-powered switch when you plug its power

supplies into grounded AC power receptacles.

Page 71

Grounding Cable Specifications for an EX9251 Switch

The grounding cable that you provide must meet the specifications in Table 29 on page 71.

Table 29: Grounding Cable Specifications

Quantity and SpecificationCable Type

Grounding

The grounding lug accommodates 14–10 AWG (2–5.3 mm²) stranded wire. The grounding cable that you provide for the chassis must be the same size or heavier than the input wire of each power supply. Minimum recommendations are 14–10 AWG (2–5.3 mm²) stranded wire, 60° C wire, or one that complies with the local code.

Grounding Lug Specifications for an EX9251 Switch

The accessory box shipped with the switch includes two screws used to secure the grounding cable to the grounding points.

USB Port Specifications for an EX Series Switch

The following Juniper Networks USB flash drives have been tested and are officially supported for the USB port on all EX Series switches:

RE-USB-1G-S

•

RE-USB-2G-S

•

RE-USB-4G-S

•

CAUTION: Any USB memory product not listed as supported for EX Series switches

has not been tested by Juniper Networks. The use of any unsupported USB memory product could expose your EX Series switch to unpredictable behavior. Juniper Networks Technical Assistance Center (JTAC) can provide only limited support for issues related to unsupported hardware. We strongly recommend that you use only supported USB flash drives.

All USB flash drives used on EX Series switches must have the following features:

USB 2.0 or later.

•

Formatted with a FAT or MS-DOS file system.

•

Page 72

If the switch is running Junos OS Release 9.5 or earlier, the formatting method must use a primary boot

•

record. Microsoft Windows formatting, by default, does not use a primary boot record. See the documentation for your USB flash drive for information about how your USB flash drive is formatted.

Console Port Connector Pinout Information for an EX9251 Switch

The console port on an EX9251 switch are RS-232 serial interfaces. This port connects the switch to a console management port.

Table 30 on page 72 provides the pinout information for the RJ-45 connector. An RJ-45 cable and an

RJ-45 to DB-9 serial port adapter are supplied with the switch.

NOTE: If your laptop or PC does not have a DB-9 plug connector pin and you want to connect

your laptop or PC directly to an EX9251 switch, use a combination of the RJ-45 to DB-9 socket adapter supplied with the switch and a USB to DB-9 plug adapter. You must provide the USB to DB-9 plug adapter.

Table 30: EX9251 Switches Console Port Connector Pinout Information

DescriptionSignalPin

Request to sendRTS1

Data terminal readyDTR2

Transmit dataTxD3

Signal groundGround4

Signal groundGround5

Receive dataRxD6

Data set readyDSR/DCD7

Clear to sendCTS8

SEE ALSO

Page 73

Connect a Device to a Management Console Using an RJ-45 Connector | 104

RJ-45 to DB-9 Serial Port Adapter Pinout Information

The console port is an RS-232 serial interface that uses an RJ-45 connector to connect to a management device such as a laptop or a desktop PC. If your laptop or desktop PC does not have a DB-9 plug connector pin and you want to connect your laptop or desktop PC to the device, use a combination of the RJ-45 to DB-9 socket adapter along with a USB to DB-9 plug adapter.

Table 31 on page 73 provides the pinout information for the RJ-45 to DB-9 serial port adapter.

Table 31: RJ-45 to DB-9 Serial Port Adapter Pinout Information

SignalDB-9 PinSignalRJ-45 Pin

CTS8RTS1

DSR6DTR2

RxD2TxD3

GND5GND4

TxD3RxD6

DTR4DSR7

RTS7CTS8

RJ-45 Management Port Connector Pinout Information

Table 32 on page 73 provides the pinout information for the RJ-45 connector for the management port

on Juniper Networks devices.

Table 32: RJ-45 Management Port Connector Pinout Information

DescriptionSignalPin

Transmit/receive data pair 1TRP1+1

Transmit/receive data pair 1TRP1—2

Page 74

Table 32: RJ-45 Management Port Connector Pinout Information (continued)

DescriptionSignalPin

Transmit/receive data pair 2TRP2+3

Transmit/receive data pair 3TRP3+4

Transmit/receive data pair 3TRP3—5

Transmit/receive data pair 2TRP2—6

Transmit/receive data pair 4TRP4+7

Transmit/receive data pair 4TRP4—8

Page 75

CHAPTER

Initial Installation and Configuration

Unpacking and Mounting the EX9251 Switch | 76

Connecting the EX9251 to Power | 88

Connecting the EX9251 to External Devices | 103

Connecting the EX9251 to the Network | 108

Configuring Junos OS on the EX9251 | 112

Page 76

Unpacking and Mounting the EX9251 Switch

IN THIS SECTION

Unpacking an EX9251 Switch | 76

Parts Inventory (Packing List) for an EX9251 Switch | 77

Installing and Connecting an EX9251 Switch | 79

Mounting an EX9251 Switch on a Rack or Cabinet | 80

Unpacking an EX9251 Switch

EX9251 switches are shipped in a cardboard carton, secured with foam packing material. The carton has an accessory compartment and contains the quick start instructions.

CAUTION: EX9251 switches are maximally protected inside the shipping carton. Do

not unpack the switches until you are ready to begin installation.

To unpack the switch:

1. Move the shipping carton to a staging area as close to the installation site as possible, but where you have enough room to remove the system components.

2. Position the carton so that the arrows are pointing up.

3. Open the top flaps on the shipping carton.

4. Remove the accessory box, and verify the contents against the parts inventory on the label attached to the carton.

5. Pull out the packing material holding the switch in place.

Page 77

6. Verify the parts received against the inventory on the label attached to the carton. See “Parts Inventory

(Packing List) for an EX9251 Switch” on page 77.

7. Save the shipping carton and packing materials in case you need to move or ship the switch later.

SEE ALSO

Installing and Connecting an EX9251 Switch | 79 Connecting and Configuring an EX9251 Switch (CLI Procedure) | 113

Parts Inventory (Packing List) for an EX9251 Switch

The switch shipment includes a packing list. Check the parts you receive in the switch shipping crate against the items on the packing list. The packing list specifies the part number and provides description of each part in your order. The parts shipped depend on the configuration you order. See “EX9251 Switch Models”

on page 24 for more information.

If any part on the packing list is missing, contact your customer service representative or contact Juniper customer care from within the U.S. or Canada by telephone at 1-888-314-5822. For international-dial or direct-dial options in countries without toll-free numbers, see

https://www.juniper.net/support/requesting-support.html .

Table 33 on page 77 lists the parts and their quantities in the packing list for a fully configured switch. Table 34 on page 78 lists the parts contained in the accessory box.

Table 33: Parts List for a Fully Configured EX9251 Switch

QuantityComponent

1Chassis

2AC or DC power supplies

3Fan trays

1Documentation Roadmap

Page 78

Table 34: Accessory Box Parts List

chassis

secure the ETSI brackets to the front-mounting brackets and rear-mounting brackets

QuantityPart

2Front-mounting brackets

2Rear-mounting brackets

16Screws to attach the front-mounting brackets to the

4ETSI brackets

8M5 Pan Head screws with integrated washers to

210-32 screws to secure the ground cable lug

location

2Ring lugs to connect to DC power source cables

1AC power cord appropriate for your geographical

1Label, “Small Parts Enclosed”

1Label, “Accessories Contents”

1USB flash drive with Junos OS

1Read me first document

1Affidavit for T1 connection

1Juniper Networks Product Warranty

1End User License Agreement

1Document sleeve

23 in. x 5 in. pink bag

29 in. x 12 in. pink bag, ESD

1Ethernet cable with an RJ-45 connector attached

Page 79

Table 34: Accessory Box Parts List (continued)

QuantityPart

1RJ-45 to DB-9 serial port adapter

1Electrostatic discharge (ESD) wrist strap with cable

Register Products—Mandatory to Validate SLAs

Register all new Juniper Networks hardware products and changes to an existing installed product using the Juniper Networks website to activate your hardware replacement service-level agreements (SLAs).

CAUTION: Register product serial numbers on the Juniper Networks website and

update the installation base data if there is any addition or change to the installation base or if the installation base is moved. Juniper Networks will not be held accountable for not meeting the hardware replacement service-level agreement for products that do not have registered serial numbers or accurate installation base data.

https://www.juniper.net/customers/csc/management/updateinstallbase.jsp.

Installing and Connecting an EX9251 Switch

The EX9251 switch chassis is a rigid sheet-metal structure that houses all components of the switch. The switch is shipped in a cardboard carton, secured with foam packing material. The carton has an accessory compartment and contains the quick start instructions.

To install and connect an EX9251 switch:

1. Unpack the switch by following instructions in “Unpacking an EX9251 Switch” on page 76.

2. Mount the switch by following instructions in “Mounting an EX9251 Switch on a Rack or Cabinet” on

page 80.

Page 80

3. Connect the switch to earth ground by following instructions in “Connect Earth Ground to an EX Series

Switch” on page 88.

4. Connect power to the switch by following instructions as appropriate for your model:

Connecting AC Power to an EX9251 Switch and Powering on the Switch on page 95

•

Connecting DC Power to an EX9251 Switch and Powering on the Switch on page 99

•

5. Perform initial configuration of the switch by following instructions in “Connecting and Configuring an

EX9251 Switch (CLI Procedure)” on page 113.

6. Set the switch’s management options by following the appropriate instructions:

Connect a Device to a Network for Out-of-Band Management on page 103

•

Connect a Device to a Management Console Using an RJ-45 Connector on page 104

•

SEE ALSO

Rack and Cabinet Requirements for EX9251 Switches | 57 Chassis and Component Lifting Guidelines | 174

Mounting an EX9251 Switch on a Rack or Cabinet

IN THIS SECTION

Mounting an EX9251 Switch on a 19-in. Rack | 81

Installing an EX9251 Switch in an ETSI Rack | 84

You can mount an EX9251 switch on four posts of a rack that complies with either of the following standards or in a cabinet with a rack that complies with either of the following standards by using the mounting brackets provided with the switch:

19-in. rack—A 19-in. (450 mm) rack as defined by the Electronic Components Industry Association

•

(http://www.ecianow.org).

ETSI rack—A 21-in. (500 mm) ETSI rack as defined in the European Telecommunications Standards

•

Institute (ETS 300 119) published by the European Telecommunications Standards Institute (ETSI).

Page 81

The remainder of this topic uses rack to mean rack or cabinet.

Before mounting the switch:

Verify that the site meets the requirements described in “Site Preparation Checklist for an EX9251

•

Switch” on page 48.

Place the rack in its permanent location, allowing adequate clearance for airflow and maintenance, and

•

secure it to the building structure.

Read “General Safety Guidelines and Warnings” on page 167, with particular attention to “Chassis and

•

Component Lifting Guidelines” on page 174.

Remove the switch from the shipping carton (see “Unpacking an EX9251 Switch” on page 76).

•

WARNING: Ensure that you understand how to prevent ESD damage. Wrap and fasten

one end of an ESD wrist strap around your bare wrist, and connect the other end of the strap to the ESD point on the switch.

CAUTION: If you are mounting multiple switches on a rack, mount a switch in the

bottom of the rack first and proceed to mount the rest of the switches from bottom to top.

NOTE: One person must be available to lift the switch while another secures the switch to the

rack. The weight of a fully configured chassis is 22.7 lb (10.3 kg).

We recommend that you install cover panels in the unused power supply slots.

Mounting an EX9251 Switch on a 19-in. Rack

Before you begin mounting the switch on a 19-in. rack, ensure that you have the following parts and tools available:

Phillips (+) screwdriver, number 2 (not provided)

•

Two front-mounting brackets and 16 screws to secure the brackets to the chassis (provided in the

•

accessory box shipped with the switch)

Two rear-mounting brackets (provided in the accessory box shipped with the switch)

•

Page 82

Eight screws to secure the chassis to the rack (not provided)

g022419

•

Cover panels for power supply slots

•

To mount the switch on a 19-in. rack:

1. Place the switch on a flat, stable surface.

2. Align the front-mounting brackets along the front panel of the switch chassis (see Figure 23 on page 82).

Figure 23: Attaching the Front-Mounting Brackets to the Switch Chassis

3. Align the bottom holes in the front-mounting brackets with the holes on the side panels of the switch chassis.

4. Insert mounting screws into the aligned holes. Tighten the screws by using the Phillips (+) screwdriver, number 2.

5. Ensure that the other holes in the front-mounting brackets are aligned with the holes in the side panels. Insert a screw in each hole and tighten the screws by using the Phillips (+) screwdriver, number 2.

6. Have one person grasp both sides of the switch, lift the switch, and position it in the rack, aligning the front-mounting bracket holes with the threaded holes in the rack posts. Align the bottom hole in both the mounting brackets with a hole in each rack post, making sure the chassis is level.

7. Have a second person secure the switch to the rack by using the appropriate screws. Tighten the screws (see Figure 24 on page 83).

Page 83

Figure 24: Mounting an EX9251 Switch on a Rack by Using Front-Mounting Brackets

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8. Ensure that the switch chassis is level by verifying that all screws on one side of the rack are aligned with the screws on the other side. Figure 25 on page 83 shows the switch mounted on a rack by using front-mounting brackets.

Figure 25: An EX9251 Switch Mounted on Rack by Using Front-Mounting Brackets

9. On the rear of the chassis, slide the rear-mounting brackets on either side of the chassis until the rear-mounting brackets contact the rack rails (see Figure 26 on page 83).

Figure 26: Mounting the Rear-Mounting Brackets

Page 84

10. Insert the screws to secure the chassis to the rack into the holes in the bracket aligned to the holes in

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the rack post, starting from the bottom. Tighten the screws by using the Phillips (+) screwdriver, number 2.

11. Visually inspect the alignment of the chassis. If the chassis is installed properly in the rack, all the mounting screws on one side of the rack are aligned with the mounting screws on the opposite side and the switch is level. Figure 27 on page 84 shows the switch fully secured and installed on four posts of a rack.

Figure 27: EX9251 Mounted on Four Posts of a 19-in. Rack

Installing an EX9251 Switch in an ETSI Rack

Before you begin mounting the switch on an ETSI rack, ensure that you have the following parts and tools available:

Phillips (+) screwdriver, number 2 (not provided)

•

Two front-mounting brackets and 16 screws to secure the brackets to the chassis (provided in the

•

accessory box shipped with the switch)

Two rear-mounting brackets (provided in the accessory box shipped with the switch)

•

Four ETSI brackets. Figure 28 on page 84 shows the ETSI brackets provided with EX9251 switches.

•

Figure 28: ETSI Brackets

Eight screws to secure the chassis to the rack (not provided)

•

Cover panels for power supply slots

•

Page 85

To mount the switch on an ETSI rack:

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g0 0 9886

1. Position the switch in front of the rack.

2. Align the front-mounting brackets along the front panel of the switch chassis (see Figure 29 on page 85.

Figure 29: Attaching the Front-Mounting Brackets to the Switch Chassis

3. Align the bottom holes in the front-mounting brackets with the holes on the side panels of the switch chassis.

4. Insert mounting screws into the aligned holes. Tighten the screws by using the Phillips (+) screwdriver, number 2.

6. Attach two ETSI brackets to the front-mounting brackets by using the M5 Pan Head screws with integrated washers (see Figure 30 on page 85).

Figure 30: Attaching ETSI Brackets to the Front-Mounting Brackets

7. Have one person grasp both sides of the switch, lift the switch, and position it in the rack, aligning the holes in the ETSI brackets attached to the front-mounting brackets with the threaded holes in the rack posts. Align the bottom hole in both the ETSI brackets with a hole in each rack post, making sure the chassis is level.

Page 86

8. Have a second person secure the switch to the rack by using the appropriate screws. Tighten the screws

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(see Figure 31 on page 86).

Figure 31: Mounting an EX9251 Switch on an ETSI Rack by Using Front-Mounting Brackets

9. Ensure that the switch chassis is level by verifying that all screws on one side of the rack are aligned with the screws on the other side. Figure 32 on page 86 shows the switch mounted on a rack by using ETSI brackets attached to the front-mounting brackets.

Figure 32: An EX9251 Switch Mounted on an ETSI Rack by Using Front-Mounting Brackets

10. Attach two ETSI brackets to the rear-mounting brackets by using the M5 Pan Head screws with integrated washers (see Figure 33 on page 86

Figure 33: Attaching ETSI Brackets to the Rear-Mounting Brackets

Page 87

11. On the rear of the chassis, slide the rear-mounting brackets (with the ETSI brackets attached) on either

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side of the chassis until the rear-mounting brackets contact the rack posts (see Figure 34 on page 87).

Figure 34: Mounting the Rear-Mounting Brackets by Using ETSI Brackets

12. Insert the screws to secure the chassis to the rack into the holes in the bracket aligned to the holes in the rack post, starting from the bottom. Tighten the screws by using the Phillips (+) screwdriver, number 2.

13. Visually inspect the alignment of the chassis. If the chassis is installed properly in the rack, all the mounting screws on one side of the rack are aligned with the mounting screws on the opposite side and the switch is level. Figure 35 on page 87 shows the switch fully secured and installed on four posts of a rack.

Figure 35: EX9251 Mounted on Four Posts of an ETSI Rack

SEE ALSO

Rack-Mounting and Cabinet-Mounting Warnings | 179

Page 88

Connecting the EX9251 to Power

IN THIS SECTION

Connect Earth Ground to an EX Series Switch | 88

Connecting AC Power to an EX9251 Switch and Powering on the Switch | 95

Connecting DC Power to an EX9251 Switch and Powering on the Switch | 99

Connect Earth Ground to an EX Series Switch

IN THIS SECTION

Parts and Tools Required for Connecting an EX Series Switch to Earth Ground | 89

Special Instructions to Follow Before Connecting Earth Ground to an EX Series Switch | 93

Connecting Earth Ground to an EX Series Switch | 94

To ensure proper operation and to meet safety and electromagnetic interference (EMI) requirements, you must connect an EX Series switch to earth ground before you connect power to the switch. You must use the protective earthing terminal on the switch chassis to connect the switch to earth ground (see

Figure 37 on page 95).

You must install the EX Series switch in a restricted–access location and ensure that the chassis is always properly grounded. EX Series switches have a two–hole protective grounding terminal provided on the chassis. See Table 35 on page 89 for the location of the earthing terminals on various EX Series switches. We recommend that you use the protective grounding terminal as the preferred method for grounding the chassis regardless of the power supply configuration. However, if additional grounding methods are available, you can also use those methods. For example, you can use the grounding wire in the power cord of an AC power supply or use the grounding terminal or lug on a DC power supply. This system was tested to meet or exceed all applicable EMC regulatory requirements with the two-hole protective grounding terminal connected correctly.

Ensure that a licensed electrician has attached an appropriate grounding lug to the grounding cable you supply. Using a grounding cable with an incorrectly attached lug can damage the switch.

Page 89

Parts and Tools Required for Connecting an EX Series Switch to Earth Ground

Before you begin connecting an EX Series switch to earth ground, ensure you have the parts and tools required for your switch.

Table 35 on page 89 lists the earthing terminal location, grounding cable and lug specifications, and parts

needed for connecting an EX Series switch to earth ground.

Table 35: Parts Required for Connecting an EX Series Switch to Earth Ground

EX2200

EX2300-C

Earthing Terminal LocationSwitch

Rear panel of the chassis

Grounding Cable Requirements

14 AWG (2 mm²), minimum 90° C wire, or as permitted by the local code

Grounding Lug Specifications

Panduit LCC10-14BWL or equivalent— not provided

Panduit LCC10-14AW-L or equivalent— not provided

Screws and Washers

Two

•

10-32 x .25 in. screws with #10 split-lock washer— not provided

Two #10 flat

•

washers—not provided

Two

•

10-32 x .25 in. screws with #10 split-lock washer— not provided

Two #10 flat

•

washers—not provided

Additional Information

Page 90

Table 35: Parts Required for Connecting an EX Series Switch to Earth Ground (continued)

EX2300

Earthing Terminal LocationSwitch

Rear panel of the chassis

Grounding Cable Requirements

EX2300

•

switches except EX2300-24MP and EX2300-48MP models—14 AWG (2 mm²), minimum 90°C wire, or as permitted by the local code

EX2300-24MP

•

and EX2300-48MP models—14-10 AWG STR (2.5-6 mm²), 12-10 AWG SOL (4-6 mm²) minimum 90°C wire, or as permitted by the local code—not provided

Grounding Lug Specifications

EX2300 switches

•

except EX2300-24MP and EX2300-48MP models—Panduit LCC10-14AW-L or equivalent—not provided

EX2300-24MP and

•

EX2300-48MP models—Panduit LCA10-10L or equivalent—not provided

Screws and Washers

EX2300

•

switches except EX2300-24MP and EX2300-48MP models

Two 10-32 x

•

.25 in. screws with #10 split-lock washer—not provided

Two #10 flat

•

washers—not provided

EX2300-24MP

•

and EX2300-48MP models

One Pan

•

Phillips M 4 x 6 mm Nickel plated screw—provided

Additional Information

EX3200, EX3300, and EX3400

Rear panel of the chassis

14 AWG (2 mm²), minimum 90° C wire, or as permitted by the local code

Panduit LCC10-14BWL or equivalent— not provided

Two

•

10-32 x .25 in. screws with #10 split-lock washer— not provided

Two #10 flat

•

washers— not provided

For EX3200 Switches, see “Special

Instructions to Follow Before Connecting Earth Ground to an EX Series Switch” on page 93.

Page 91

Table 35: Parts Required for Connecting an EX Series Switch to Earth Ground (continued)

EX4200, EX4500, and EX4550

EX6210

Earthing Terminal LocationSwitch

Left side of the chassis

Rear panel of the chassis (on lower left side)

Grounding Cable Requirements

14 AWG (2 mm²), minimum 90° C wire, or as permitted by the local code

The grounding cable must be the same gauge as the power feed cables and as permitted by the local code.

Grounding Lug Specifications

Panduit LCC10-14BWL or equivalent— not provided

Panduit LCD2-14A-Q or equivalent —provided

Screws and Washers

Two 10-32

•

x .25 in. screws with #10 split-lock washer— not provided

Two #10 flat

•

washers— not provided

Two ¼ -20

•

x 0.5 in. screws with #¼” split-washer —provided

Two #¼” flat

•

washers— provided

Additional Information

See “Special

Instructions to Follow Before Connecting Earth Ground to an EX Series Switch” on page 93.

EX8208

Left side of the chassis

6 AWG (13.3 mm²), minimum 90° C wire, or as permitted by the local code

Panduit LCD2-14A-Q or equivalent —provided

Two ¼ -20

•

x 0.5 in. screws with #¼” split-washer —provided

Two #¼” flat

•

washers— provided

Page 92

Table 35: Parts Required for Connecting an EX Series Switch to Earth Ground (continued)

EX8216

EX9204, EX9208, and EX9214

Earthing Terminal LocationSwitch

Two earthing terminals:

Left side of

•

the chassis

Rear panel

•

of the chassis

NOTE: You

must use only one of the two protective earthing terminals.

Rear panel of the chassis

Grounding Cable Requirements

2 AWG (33.6 mm²), minimum 90° C wire, or as permitted by the local code

One 6 AWG (13.3 mm²), minimum 90° C wire, or one that complies with the local code

Grounding Lug Specifications

Panduit LCD2-14A-Q or equivalent —provided

Thomas& Betts LCN6-14 or equivalent— provided

Screws and Washers

Two ¼ -20 x

•

0.5 in. screws with #¼” split-washer —provided

Two #¼” flat

•

washers— provided

Two ¼ -20

•

x 0.5 in. screws with #¼” split-washer— provided

Two #¼” flat

•

washers— provided

Additional Information

See Grounding Cable

and Lug Specifications for EX9200 Switches.

EX9251

Rear panel of the chassis

12 AWG (2.5 mm²), minimum 90° C wire, or one that complies with the local code— not provided

Panduit LCD10-10A-L or equivalent— not provided

Two 10-32 screws— provided

See Grounding Cable

and Lug Specifications for EX9200 Switches.

Page 93

Table 35: Parts Required for Connecting an EX Series Switch to Earth Ground (continued)

Grounding Cable Requirements

14-10 AWG (2-5.3 mm²), minimum 90° C wire, or one that complies with the local code— not provided

Grounding Lug Specifications

Panduit LCD10-14B-L or equivalent— provided

Screws and Washers

Two M5 Pan Head screws— provided

Additional Information

EX9253

Earthing Terminal LocationSwitch

Right side of the chassis

Tools required for connecting an EX Series switch to earth ground:

An electrostatic discharge grounding strap (provided)

•

A Phillips (+) number 2 screwdriver to tighten the screws.

•

An AC–powered EX Series switch gains additional grounding when you plug the power supply in the switch into a grounded AC power outlet by using an AC power cord appropriate for your geographical location.

Special Instructions to Follow Before Connecting Earth Ground to an EX Series Switch

Table 36 on page 93 lists the special instructions that you might need to follow before connecting earth

ground to a switch.

Table 36: Special Instructions to Follow Before Connecting Earth Ground to an EX Series Switch

Special InstructionsSwitch

EX3200 and EX4200

Some early variants of EX3200 and EX4200 switches for which the Juniper Networks model number on the label next to the protective earthing terminal is from 750-021xxx through 750-030xxx require 10-24x.25 in. screws.

Page 94

Table 36: Special Instructions to Follow Before Connecting Earth Ground to an EX Series Switch (continued)

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Special InstructionsSwitch

EX4200, EX4500, and EX4550

If you plan to mount your switch on four posts of a rack or cabinet, mount your switch in the rack or cabinet before attaching the grounding lug to the switch.

NOTE: The protective earthing terminal on switches mounted on four posts of a rack is

accessible through the slot on the left rear bracket only if the rack is 27.5 in. (69.85 cm) through

30.5 in. (77.47 cm) deep for a switch mounted flush with the rack front and 29.5 in. (74.93 cm) through 32.5 in. (82.55 cm) deep for a switch mounted 2 in. (5.08 cm) recessed from the rack front. See Figure 36 on page 94.

Figure 36: Connecting the Grounding Lug to a Switch Mounted on Four Posts of a Rack

3—1— Grounding lugProtective earthing terminal

4—2— Rear mounting-bladeSide mounting-rail

NOTE: The brackets must be attached to the chassis before the grounding lug is attached. (The

brackets are shown pulled away from the chassis so that the protective earthing terminal is seen.)

Connecting Earth Ground to an EX Series Switch

To connect earth ground to an EX Series switch:

1. Verify that a licensed electrician has attached the cable lug to the grounding cable.

2. Connect one end of the grounding cable to a proper earth ground, such as the rack in which the switch is mounted.

Page 95

3. Attach an ESD grounding strap to your bare wrist, and connect the strap to the ESD grounding point

g020647

Screw

(with split

washer)

Grounding lug

on the switch.

4. Place the grounding lug attached to the grounding cable over the protective earthing terminal. See

Figure 37 on page 95.

Figure 37: Connecting a Grounding Cable to an EX Series Switch

5. Secure the grounding lug to the protective earthing terminal with the washers and screws.

6. Dress the grounding cable and ensure that it does not touch or block access to other switch components and that it does not drape where people could trip over it.

SEE ALSO

General Safety Guidelines and Warnings | 167 Grounded Equipment Warning | 185

Connecting AC Power to an EX9251 Switch and Powering on the Switch

You can install up to two AC power supplies in an EX9251 switch. The AC power supply in an EX9251 switch is a hot-removable and hot-insertable field-replaceable unit (FRU). You can remove and replace it while the switch is running without turning off power to the switch or disrupting switching functions. The power supplies install in the slots on the rear panel of the chassis.

Page 96

CAUTION: Do not mix AC and DC power supplies in the same chassis.

Before you begin to connect power to the switch:

Ensure you understand how to prevent electrostatic discharge (ESD) damage. See “Prevention of

•

Electrostatic Discharge Damage” on page 201.

Ensure that you have connected the device chassis to earth ground.

•

CAUTION: For installations that require a separate grounding conductor to the

chassis, have a licensed electrician complete this connection before you connect the switch to power. For instructions on connecting earth ground, see “Connect Earth

Ground to an EX Series Switch” on page 88.

Install AC power supplies in the switch. See “Installing an AC Power Supply in an EX9251 Switch” on

•

page 128.

Ensure that you have the following parts and tools available to connect power to the switch and to power it on:

An ESD wrist strap

•

Power cords appropriate for your geographical location (provided). See “AC Power Cord Specifications

•

for an EX9251 Switch” on page 42.

An external management device

•

NOTE: Each power supply must be connected to a dedicated AC power feed with a dedicated

customer-site circuit breaker. We recommend that you use a dedicated customer-site circuit breaker rated for 20 A (110 VAC) or 16 A (220 VAC) minimum, or as required by local code.

To connect AC power to an EX9251 switch (see Figure 40 on page 98):

1. Wrap and fasten one end of the ESD wrist strap around your bare wrist, and connect the other end of the strap to the ESD point on the switch.

2. Ensure that the power supply is fully inserted and latched securely in the chassis. See “Installing an AC

Power Supply in an EX9251 Switch” on page 128.

3. If the AC power source outlet has a power switch, set it to the off position.

Page 97

4. Push the end of the AC power cord retainer strip into the AC power cord retainer port (see

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Figure 38 on page 97) next to the inlet on the power supply faceplate until it snaps into place. Ensure

that the loop in the retainer strip faces toward the power cord.

Figure 38: Power Cord Retainer Port on the AC Power Supply Faceplate

4—1— Fault LEDHandle

5—2— Ejector leverInput status LED

6—3— AC power cord retainer portOutput status LED

Figure 39 on page 97 shows the power cord retainer installed on the AC power supply.

Figure 39: Power Cord Retainer Installed on the AC Power Supply

4—1— Fault LEDHandle

5—2— AC power cord retainerInput status LED

6—3— Ejector leverOutput status LED

5. Press the small tab on the retainer strip to loosen the loop. Slide the loop until you have enough space to insert the power cord coupler into the inlet.

6. Insert the power cord plug firmly into the power cord inlet.

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7. Slide the loop toward the power supply until it is snug against the base of the coupler.

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8. Press the tab on the loop and draw out the loop into a tight circle (see Figure 40 on page 98).

Figure 40: Connecting the AC Power Supply Cord to an AC-Powered Switch

9. Dress the power cord appropriately. Verify that the power cords do not block access to switch components or drape where people can trip on them.

10. Insert the power cord plug into the power source outlet.

11. Connect the console port on the switch (labeled CON) to the external management device.

12. Turn on power to the external management device.

13. Switch on the dedicated customer-site circuit breakers for the power supply. Follow the instructions for your site.

14. If the AC power source outlet has a power switch, set it to the on position.

NOTE: After powering off a power supply, wait at least five seconds before turning it back

on. After powering on a power supply, wait at least five seconds before turning it off.

If the switch is completely powered off when you power on the power supply, the Routing Engine boots as the power supply completes its startup sequence. If the Routing Engine finishes booting and you need to power off the system again, first issue the CLI request vmhost power-off command. After a power supply is powered on, it can take up to five seconds for status indicators—such as the LEDs on the power supply and the show chassis command display—to indicate that the power supply is functioning normally. Ignore error indicators that appear during the first five seconds.

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15. If the power supply is installed correctly and functioning normally, the input status LED labeled AC and output status LED labeled DC on the power supply faceplate are on and steadily lit green, and the alarm LED (labeled !) is not lit.

16. On the external management device, monitor the startup process to verify that the switch has booted properly.

SEE ALSO

Power Supplies in an EX9251 Switch | 36

Connecting DC Power to an EX9251 Switch and Powering on the Switch

You can install up to two DC power supplies in an EX9251 switch. The DC power supply in an EX9251 switch is a hot-removable and hot-insertable field-replaceable unit (FRU). You can remove and replace it while the switch is running without turning off power to the switch or disrupting switching functions. The power supplies install in the slots on the rear panel of the chassis.

CAUTION: Do not mix AC and DC power supplies in the same chassis.

WARNING: Before performing DC power procedures, ensure that power is removed

from the DC circuit. To ensure that all power is off, locate the circuit breaker on the panel board that services the DC circuit, switch the circuit breaker to the off position, and tape the switch handle of the circuit breaker in the off position.

CAUTION: Before you connect power to the switch, a licensed electrician must attach

cable lugs to the grounding and power cables that you supply. A cable with an incorrectly attached lug can damage the switch (for example, by causing a short circuit).

Before you begin connecting DC power to an EX9251 switch:

Ensure that you have taken the necessary precautions to prevent electrostatic discharge (ESD) damage

•

(see “Prevention of Electrostatic Discharge Damage” on page 201).

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Ensure that you have connected the switch chassis to earth ground.

•

CAUTION: To meet safety and electromagnetic interference (EMI) requirements

and to ensure proper operation, you must connect EX9251 switches to earth ground before you connect them to power. For installations that require a separate grounding conductor to the chassis, use the protective earthing terminal on the switch chassis to connect to earth ground. For instructions on connecting an EX9251 switch to ground using a separate grounding conductor, see “Connect Earth Ground to an EX

Series Switch” on page 88.

Install DC power supplies in the chassis. See “Installing a DC Power Supply in an EX9251 Switch” on

•

page 131.

Ensure that you have the following parts and tools available to connect DC power to an EX9251 switch:

An ESD wrist strap

•

100

DC power source cables (minimum 12 AWG (2.5 mm²), minimum 60°C wire or as permitted by local

•

code)

Two ring lugs (Molex 01907000969 or equivalent)—provided with the switch

•

An external management device

•

Phillips (+) screwdriver, number 2

•

A multimeter

•

NOTE: Each power supply input feed must be connected to a dedicated DC power source outlet.

To connect DC power to an EX9251 switch (see Figure 41 on page 102):

1. Switch off the dedicated customer site circuit breakers. Ensure that the voltage across the DC power source cable leads is 0 V and that there is no chance that the cable leads might become active during installation.

2. Wrap and fasten one end of the ESD wrist strap around your bare wrist, and connect the other end of the strap to the ESD point on the switch.

3. Remove the plastic cover from the terminal block on the power supply faceplate.

4. Verify that the DC power cables are correctly labeled before making connections to the power supply. In a typical power distribution scheme where the return is connected to chassis ground at the battery

Juniper EX9251 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

Table of Contents

About the Documentation

Documentation and Release Notes

Using the Examples in This Manual

Merging a Full Example

Merging a Snippet

Documentation Conventions

Documentation Feedback

Requesting Technical Support

Self-Help Online Tools and Resources

Creating a Service Request with JTAC

Overview

EX9251 System Overview

EX9251 Switch Hardware Overview

Software

Benefits of the EX9251 Switch

EX9251 Switch Models

Front Panel of an EX9251 Switch

Rear Panel of an EX9251 Switch

Routing Engine

Power Supplies

Cooling System

Component Redundancy

EX9251 Switch Models

EX9251 Switch Hardware and CLI Terminology Mapping

EX9251 Chassis

Chassis Physical Specifications of an EX9251 Switch

Field-Replaceable Units in an EX9251 Switch

LEDs on the Front Panel of an EX9251 Switch

EX9251 Cooling System

Fan Trays

Airflow Direction in the EX9251 Switch Chassis

Cooling System in the Power Supplies

Fan Tray Status LEDs

EX9251 Power System

Power Supplies in an EX9251 Switch

AC Power Supply Description

AC Power Supply LEDs and Other Components

DC Power Supply Description

DC Power Supply LEDs and Other Components

AC Power Cord Specifications for an EX9251 Switch

Power Requirements for EX9251 Switch Components

Power Requirements for EX9251 Switch Components

Calculating System Thermal Output

Power Supply Specifications for EX9251 Switches

Site Preparation Checklist for an EX9251 Switch

EX9251 Site Guidelines and Requirements

Environmental Requirements and Specifications for EX Series Switches

General Site Guidelines

Site Electrical Wiring Guidelines

Rack and Cabinet Requirements for EX9251 Switches

EX9251 Network Cable and Transceiver Planning

Pluggable Transceivers Supported on EX9251 Switches

SFP+ Direct Attach Copper Cables for EX Series Switches

Cable Specifications

List of DAC Cables Supported on EX Series Switches

Standards Supported by These Cables

QSFP+ Direct Attach Copper Cables for EX Series Switches

Cable Specifications

DAC Cables Supported on EX3400, EX4300, EX4550, EX4600, EX9251, and EX9253 Switches

Understanding EX Series Switches Fiber-Optic Cable Signal Loss, Attenuation, and Dispersion

Signal Loss in Multimode and Single-Mode Fiber-Optic Cable

Attenuation and Dispersion in Fiber-Optic Cable

Calculating the Fiber-Optic Cable Power Budget for EX Series Devices

Calculating the Fiber-Optic Cable Power Margin for EX Series Devices

EX9251 Management Cable Specifications and Pinouts

Management Cable Specifications

Specifications of Cables and Wires That Connect to Ports on the Front Panel in an EX9251 Switch

Grounding Cable and Lug Specifications for EX9251 Switches

Grounding Points Specifications for an EX9251 Switch

Grounding Cable Specifications for an EX9251 Switch

Grounding Lug Specifications for an EX9251 Switch

USB Port Specifications for an EX Series Switch

Console Port Connector Pinout Information for an EX9251 Switch

RJ-45 to DB-9 Serial Port Adapter Pinout Information

RJ-45 Management Port Connector Pinout Information