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EX9251 System Overview

 

EX9251 Switch Hardware Overview

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.

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.

Front Panel of an EX9251 Switch

Figure 1 shows the front panel of an EX9251 switch.

Figure 1: Front Panel of an EX9251 Switch
Front Panel
of an EX9251 Switch
  1
Rate-selectable ports—These ports can operate in 100G, 40G, and 10G speeds and support transceivers and direct attach copper (DAC) cables.
  9
Reset button—button to reset the switch.
  2
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.
10
SSD0 LED—indicates the status of the solid-state drive labeled SSD0.
  3
BITS ports with LEDs—Building-integrated timing supply (BITS) external clocking port, that connects the switch to external clocking devices.
11
Alarm LED—indicates alarms.
  4
USB port—USB port, that provides a removable media interface that you can use to install Junos OS manually. Junos OS supports USB version 1.0 and later.
12
OK/Fail LED—indicates the status of the switch.
  5
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.
13
Time of day (ToD) port with LED—ToD port, that connects the switch to external timing signal sources.
  6
Online LED—indicates the status of the switch and the operating system.
14
Console port—Console port, that connects the switch to a system console through a serial cable with an RJ-45 connector.
  7
SSD1 LED—indicates the status of the solid-state drive labeled SSD1.
15
10-Gigabit Ethernet SFP+ ports—support SFP+ transceivers and direct attach copper (DAC) cables.
  8
Offline button—button to turn the switch online or offline or to power on or power off the switch.
16
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.

Rear Panel of an EX9251 Switch

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

Figure 2: Rear Panel of an EX9251 Switch with AC Power Supply
Rear Panel
of an EX9251 Switch with AC Power Supply
  1
Protective earthing terminal
  4
Fan tray LEDs
  2
Electrostatic discharge (ESD) point
  5
AC power supply units
  3
Fan trays
 
Figure 3: Rear Panel of an EX9251 Switch with DC Power Supply
Rear Panel
of an EX9251 Switch with DC Power Supply
  1
Fan trays
  2
DC power supply units

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

  • 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.

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.

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.

EX9251 Switch Models

EX9251 is available in two models—with AC power supply and with DC power supply. Table 1 lists the models and the components included in each model.

Table 1: EX9251 Switch Models

Switch Models

Configuration Components

First Junos OS Release

EX9251-8X4C

  • Chassis

  • Three fan trays

  • Two AC power supplies

18.1R1

EX9251-8X4C-DC

  • 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 2.

Table 2: CLI Equivalents of Terms Used in Documentation for EX9251 Switches

Hardware Item (CLI)

Description (CLI)

Value (CLI)

Item in Documentation

Additional Information

Chassis

EX9251

Switch chassis

Chassis Physical Specifications of an EX9251 Switch

Routing Engine

EX9251-RE

0

Routing Engine

EX9251 Switch Hardware Overview

CB

EX9251

0

Routing Engine

EX9251 Switch Hardware Overview

FPC

FPC

0

PIC (n)

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

  • 4XQSFP28 PIC

  • 8XSFPP PIC

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

Xcvr (n)

Abbreviated name of the transceiver.

n is a value equivalent to the number of the port in which the transceiver is installed.

Optical transceivers

Hardware Compatibility Tool page for EX9251

PEM (n)

One of the following:

  • AC AFO 650W PSU

  • JPSU-650W-DC-AFO

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

AC or DC power supply

Power Supplies in an EX9251 Switch

Fan tray (n)

Fan Tray, Front to Back Airflow - AFO

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

Fan tray

EX9251 Cooling System

Table 3 lists the spare parts and blank panels available for the switch. They must be ordered separately.

Table 3: Spare Parts and Blank Panels

Model Number

Description

EX9251-CHAS

EX9251 chassis, spare

JNP-PWR-BLNK-1

EX9251 power supply slot blank panel