Transition Networks SM24T6DPA User manual

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SM24T6DPA
Managed Layer 2 Gigabit Ethernet Switch
(20) 10/100/1000Base-T Ports + (4) 100/1000Base-X SFP/RJ-45
Combo Ports + (2) 100/1000Base-X SFP Slots
Install Guide
33664 Rev. B

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Safety Warnings and Cautions
These products are not intended for use in life support products where failure of a product could
reasonably be expected to result in death or personal injury. Anyone using this product in such an
application without express written consent of an officer of Transition Networks does so at their own
risk and agrees to fully indemnify Transition Networks for any damages that may result from such use
or sale.
Attention: this product, like all electronic products, uses semiconductors that can be damaged by
ESD (electrostatic discharge). Always observe appropriate precautions when handling.
NOTE: Emphasizes important information or calls your attention to related features or
instructions.
WARNING: Alerts you to a potential hazard that could cause personal injury.
CAUTION: Alerts you to a potential hazard that could cause loss of data or damage the system
or equipment.
SM24T6DPA Managed Layer 2 Gigabit Ethernet Switch Install Guide, 33664 Rev. B
Record of Revisions
Rev
Date
Description of Changes
A
11/24/15
Initial release for software v v6.46.
B
9/5/19
Revise Product Label to include UL certification. Add power connection
information. Update to FW v 6.54.3202.
Trademark notice: All trademarks and registered trademarks are the property of their
respective owners. All other products or service names used in this publication are for
identification purposes only and may be trademarks or registered trademarks of their
respective companies. All other trademarks or registered trademarks mentioned herein are
the property of their respective holders.
Copyright restrictions: © 2015-2019 Transition Networks, Inc. All rights reserved. No part of
this work may be reproduced or used in any form or by any means (graphic, electronic, or
mechanical) without written permission from Transition Networks.
Address comments on this product or manual to: Transition Networks Inc.
10900 Red Circle Drive, Minnetonka, MN 55343 | Telephone: [phone] / Toll Free:
800-526-9267 / Fax: [phone] | E-Mail: [e-mail] /

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Contents
Safety Warnings and Cautions..................................................................................................... 2
Contents ...................................................................................................................................... 3
Introduction................................................................................................................................. 5
Overview ................................................................................................................................. 5
Hardware Description.................................................................................................................. 5
Switch Architecture................................................................................................................. 5
Network Management Options .............................................................................................. 5
Front Panel .............................................................................................................................. 6
Back Panel ............................................................................................................................... 6
1000BASE-T Ports.................................................................................................................... 6
SFP Transceiver Slots ............................................................................................................... 6
Port and System Status LEDS................................................................................................... 7
Port Status LEDs .................................................................................................................. 7
System Status LED............................................................................................................... 7
Power Supply Socket ............................................................................................................... 7
Network Planning ........................................................................................................................ 7
Introduction to Switching........................................................................................................ 7
Application Examples .............................................................................................................. 8
Installing the Switch..................................................................................................................... 8
Selecting a Site ........................................................................................................................ 8
Ethernet Cabling...................................................................................................................... 9
Equipment Checklist................................................................................................................ 9
Package Contents................................................................................................................ 9
Mounting............................................................................................................................... 11
Rack Mounting.................................................................................................................. 11
Desktop or Shelf Mounting:.............................................................................................. 12
Installing an Optional SFP Transceiver .................................................................................. 12
Connecting to the Console Port ............................................................................................ 13
Serial Cable Wiring............................................................................................................ 13
Plug in the Console Port.................................................................................................... 13
Connecting to a Power Source .............................................................................................. 14
Inserting the Power Cord to AC Power Socket.................................................................. 14
Web-based Management.......................................................................................................... 15
Making Network Connections ................................................................................................... 15
Connecting Network Devices ................................................................................................ 15
Twisted-Pair Devices ......................................................................................................... 15
Cabling Guidelines ............................................................................................................ 15
Connecting to PCs, Servers, Hubs and Switches ................................................................... 16
Network Wiring Connections................................................................................................ 16
Fiber Optic SFP ...................................................................................................................... 17
Cable Labeling and Connection Records........................................................................... 18
Troubleshooting......................................................................................................................... 19
Basic Troubleshooting Tips.................................................................................................... 19
Troubleshooting Chart........................................................................................................... 20
Troubleshooting Power and Cooling Problems ..................................................................... 20
Installation ........................................................................................................................ 20

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In-Band Access.................................................................................................................. 20
Cables .................................................................................................................................... 21
Twisted-Pair Cable and Pin Assignments .......................................................................... 21
RJ-45 Connector Pin Numbers .......................................................................................... 21
10/100BASE-TX MDI and MDI-X Port Pinouts................................................................... 21
10/100BASE-TX MDI and MDI-X Port Pinouts................................................................... 22
Cable Testing for Existing Category 5 Cable ...................................................................... 22
Adjusting Existing Cat 5 Cabling to Run 1000BASE-T........................................................ 22
Specifications............................................................................................................................. 23
Physical Characteristics ......................................................................................................... 23
Switch Features ..................................................................................................................... 24
Management Features .......................................................................................................... 24
Standards .............................................................................................................................. 24
Compliance................................................................................................................................ 24
FCC-CLASS A .......................................................................................................................... 25
CE MARK DECLARATION OF CONFORMANCE FOR EMI AND SAFETY (EEC)........................... 25
EMC ....................................................................................................................................... 25

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Introduction
Overview
The SM24T6DPA 24-Port Switch is an affordable managed switch that provides a reliable
infrastructure for your business network. The switch delivers intelligent features to improve
the availability of your critical business applications, protect your sensitive information, and
optimize your network bandwidth to deliver information and applications more effectively.
Easy to set up and use, it provides the ideal combination of affordability and capabilities to
your Networking includes Small Business or enterprise application and helps you create a
more efficient, better-connected workforce.
PURPOSE
This guide gives specific information on how to operate and use the management functions of
the switch.
AUDIENCE
The guide is intended for use by network administrators who are responsible for operating and
maintaining network equipment; consequently, it assumes a basic working knowledge of
general switch functions, the Internet Protocol (IP), and Simple Network Management Protocol
(SNMP).
RELATED MANUALS
The following manuals give specific information on how to operate the switch:
•SM24T6DPA Quick Start Guide, 33670
•SM24T6DPA User Guide, 33666
•SM24T6DPA CLI Reference, 33665
•Release Notes (version specific)
Hardware Description
Switch Architecture
The switch performs a wire-speed, non-blocking switching fabric. This allows wire-speed
transport of multiple packets at low latency on all ports simultaneously. The switch also
features full-duplex capability on all ports, which effectively doubles the bandwidth of each
connection. This switch uses store-and-forward technology to ensure maximum data integrity.
With this technology, the entire packet must be received into a buffer and checked for validity
before being forwarded. This prevents errors from being propagated throughout the network
Network Management Options
The switch can also be managed over the network with a web browser or Telnet application.
The switch includes a built-in network management agent that allows it to be managed in-
band using SNMP or RMON (Groups 1, 2, 3, 9) protocols. It also has an RJ45 console port
connector on the front panel for out-of-band management. A PC may be connected to this
port for configuration and monitoring out-of-band via a null-modem serial cable. See
Appendix B for wiring options.
NOTE: For a detailed description of the management features, see the Web User Guide.

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Front Panel
Back Panel
1000BASE-T Ports
The switch contains 24 10/100/1000BASE-T RJ-45 ports. All RJ-45 ports support automatic
MDI/MDI-X operation, auto-negotiation and IEEE 802.3x auto-negotiation of flow control, so
the optimum data rate and transmission can be selected automatically
SFP Transceiver Slots
SM24T6DPA supports the Small Form Factor Pluggable (SFP) transceiver slots are shared
with RJ-45 port 21 to 24. In the default configuration, if an SFP transceiver (purchased
separately) is installed in a slot and has a valid link on the port, the associated RJ-45 port is
disabled. For more SFP information, see the TN SFP webpage at
https://www.transition.com/lines/optical-devices/platform-sfp/

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Port and System Status LEDS
The SM24T6DPA switch includes a display panel for system and port indications that simplify
installation and network troubleshooting. The LEDs are located on left side of the front panel
for easy viewing. Details are shown below and described in the following tables.
Port Status LEDs
LED
Condition
Status
TP (Link/ACT)
Green
Lit Green when TP link good
Blinks when any traffic is present
TP SPEED
Green
Lit Green when TP link on 1000Mbps
Blinks when TP link on 100Mbps
Off when TP link on 10Mbps
SFP (Link/ACT)
Green/Amber
Lit Green when SFP link on 1000Mbps speed
Lit Amber when SFP link on 100Mbps speed
Blinks when any traffic is present
System Status LED
LED
Condition
Status
Power
Green Off
Lit when power is coming up
Power Supply Socket
There is a power socket on the rear panel of the switch. For normal power supply, the
SM24T6DPA Switch has standard power socket for AC power cord.
Power Cord Included: To order the corresponding country-specific power cord, add the
extension to the end of the SKU; for example, SM24T6DPA-NA = North America, -LA = Latin
America, -EU = Europe, -UK = United Kingdom, -SA = South Africa, -JP = Japan, -OZ =
Australia, and -BR = Brazil.
Network Planning
Introduction to Switching
A network switch allows simultaneous transmission of multiple packets; it can partition a
network more efficiently than bridges or routers. Therefore, the switch has been recognized
as one of the most important devices for today’s networking technology.
When performance bottlenecks are caused by congestion at a network access point such as a
file server, the device can be connected directly to a switched port. And, by using full-duplex
mode, the bandwidth of the dedicated segment can be doubled to maximize throughput.
When networks are based on repeater (hub) technology, the distance between end stations is
limited by a maximum hop count. However, a switch can subdivide the network into smaller,
more manageable segments, and link them to the larger network; it then turns the hop count
back to zero and removes the limitation.
A switch can be easily configured in any Ethernet, Fast Ethernet, or Gigabit Ethernet network
to significantly increase bandwidth while using conventional cabling and network cards.

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Application Examples
The SM24T6DPA switch has 24 Gigabit copper ports and two 100/1000 dual speed SFPs. It is
designed to segment your network, and to provide a wide range of options in setting up
network connections. Some typical applications are:
•Work group switch used in Enterprise or SMB
•Peer-to-peer application used in two remote offices
•Office network
•High Performance requirement environment
•Advance security for network safety application
•Data/voice and video conference application
Installing the Switch
Selecting a Site
The switch can be mounted on a flat surface or in a standard 19-inch rack using mounting
brackets. Follow the guidelines below when choosing a location. The site should:
• Be at the center of all the devices you want to link and near a power outlet.
• Be able to maintain its temperature within 0 to 40°C (32 to 104 °F) and its humidity
within 10% to 90%, non-condensing.
• Be accessible for installing, cabling and maintaining the devices.
• Allow the status LEDs to be clearly visible.
Make sure the twisted-pair Ethernet cable is always routed away from power lines, radios,
transmitters or any other electrical interference.
Make sure that SM24T6DPA Switch is connected to a separate grounded power outlet that
provides 100 to 240 VAC, 50 to 60 Hz.

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Ethernet Cabling
To ensure proper operation when installing the switch into a network, make sure that the
current cables are suitable for 100BASE-TX or 1000BASE-T operation. Check the following
criteria against the current installation of your network:
• Cable type: Unshielded twisted pair (UTP) or shielded twisted pair (STP) cable with RJ-
45 connectors; Category 5 or Category 5e with maximum length of 100 meters is
recommend 100BASE-TX, and Category 5e or 6 with maximum length of 100 meters is
recommend for 1000BASE-T.
• Protection from radio frequency interference emissions.
• Electrical surge suppression.
• Separation of electrical wires and data based network wiring.
• Safe connections with no damaged cables, connectors or shields.
RJ-45 Connections SFP Transceiver
Equipment Checklist
After unpacking this switch, check the contents to be sure you have received all the
components. Then, before beginning the installation, be sure you have all other necessary
installation equipment.
Package Contents
•SM24T6DPA Management Switch
•Four adhesive rubber feet
•Mounting Accessory (for 19” Rack Shelf)
•Documentation Post card
•Printed Quick Start Guide
•AC Power Cord
•RS-232 to RJ-45 Console Cable
Notify your sales representative immediately if any of these items are missing or damaged

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WARNING: The mini-GBICs are Class 1 laser devices. Avoid direct eye exposure to the
beam coming from the transmit port.
CAUTION: Circuit devices are sensitive to static electricity, which can damage their
delicate electronics. Dry weather conditions or walking across a carpeted floor may cause you
to acquire a static electrical charge. To protect your device, always:
•Touch the metal chassis of your computer to ground the static electrical charge before you
pick up the circuit device.
•Pick up the device by holding it on the left and right edges only.
•If you need using outdoor device connect to this device with cable then you need to
addition an arrester on the cable between outdoor device and this device.
Add an arrester between outdoor device and this switch
NOTE: The switch is indoor device; if it will be used in outdoor environment or
connects with some outdoor device, then it must use a lightning arrester to protect the switch
WARNING:
•Self-demolition on Product is strictly prohibited. Damage caused by self-demolition will
be charged for repairing fees.
•Do not place product outdoor or in a sandstorm.
•Before installation, make sure input power supply and product specifications are
compatible.
•To reduce the risk of electric shock, disconnect all AC or DC power cord and RPS cables
to completely remove power from the unit.
•Before importing / exporting configuration make sure the firmware version is the same.
•After firmware upgrade, the switch will automatically change the configuration to latest
firmware version.

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Mounting
The switch can be mounted in a standard 19-inch equipment rack or on a desktop or shelf.
Mounting instructions for each type of site as follows.
Rack Mounting
•Temperature: Since the temperature within a rack assembly may be higher than the
ambient room temperature, check that the rack-environment temperature is within the
specified operating temperature range (0 to 40 °C).
•Mechanical Loading: Do not place any equipment on top of a rack-mounted unit.
•Circuit Overloading: Be sure that the supply circuit to the rack assembly is not
overloaded.
•Grounding: Rack-mounted equipment should be properly grounded.
Step 1. Attach the brackets to the device using the screws provided in the Mounting
Accessory.
Step 2. Mount the device in the rack (Via Optional Rack-Mount kit), using four rack-mounting
screws (not provided). Be sure to secure the lower rack-mounting screws first to prevent the
brackets being bent by the weight of the switch.
Step 3. If installing a single switch only, turn to “Connection to a Power Source” at the end of
this chapter.
Step 4. If installing multiple switches, mount them in the rack, one below the other, in any
order

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Desktop or Shelf Mounting:
Step 1. Attach the four adhesive rubber feet to the bottom of the first switch.
Step 2. Set the device on a flat surface near an AC power source; make sure there are at least
two inches of space on all sides for proper air flow.
Step 3. If installing a single switch only, go to “Connecting to a Power Source” at the end of
this chapter.
Step4. If installing multiple switches, attach four adhesive feet to each one. Place each device
squarely on top of the one below, in any order.
Installing an Optional SFP Transceiver
You can install or remove an SFP without having to power off the switch. The SFP is hot-
pluggable. Inserting an SFP Transceiver into an open SFP slot:
Step 1. Consider network and cabling requirements to select an appropriate SFP transceiver.
Step 2. Insert the transceiver with the optical connector facing outward and the slot
connector facing down. Note that SFP transceivers are keyed so they can only be installed in
one orientation.
Step 3. Slide the SFP transceiver into the slot until it clicks into place.
NOTE: SFP transceivers are not provided in the switch package.

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Connecting to the Console Port
The RJ-45 serial port on the switch’s front panel is used to connect to the switch for out-of-
band console configuration. The command line driven configuration program can be
accessed from a terminal or a PC running a terminal emulation program. The pin
assignments used to connect to the serial port are provided below.
Serial Cable Wiring
Switch’s 8-Pin Serial Port
Null Modem
PC’s 9-Pin DTE Port
2 RXD (receive data)
-----------------
3 TXD (transmit data)
3 RXD (receive data)
-----------------→
2 RXD (receive data)
5 SGND (Signal ground)
-------------------
5 SGND (Signal ground)
NOTE: No other pins are used.
Plug in the Console Port
The serial port’s configuration requirements are:
• Default Baud rate—115,200 bps
• Character Size—8 Characters
• Parity—None
• Stop bit—One
• Data bits—8
• Flow control—none

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Connecting to a Power Source
You can plug or remove the power cord from an AC power socket to turn power on and off.
Inserting the Power Cord to AC Power Socket
Step 1. Insert the power cable plug directly into the AC Socket located at the back of the
switch.
Step 2. Plug the other end of the cable into a grounded, 3-Pin, AC power source.
Step 3. Check the front-panel LEDs as the device is powered on to be sure the POWER LED is
lit. If not, check that the power cable is correctly plugged in.
WARNING: For International use, you may need to change the AC line cord. You must
use a line cord set that has been approved for the socket type in your country.

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Web-based Management
The switch default values are listed below:
IP Address 192.168.1.77
Subnet Mask 255.255.255.0
Default Gateway 192.168.1.254
Username admin
Password admin
After the managed switch has been configured in the CLI via the switch’s serial interface, you
can browse it. Type 192.168.1.77 in the address row in a browser; the following screen
displays, prompting you for a username and password.
The default username and password are both “admin”. For first time use, enter the default
username and password, and then click the Login button.
The login process now is complete.
Making Network Connections
Connecting Network Devices
The switch is designed to be connected to 10, 100 or 1000Mbps network cards in PCs and
servers, as well as to other switches and hubs. It may also be connected to remote devices
using optional SFP transceivers.
Twisted-Pair Devices
Each device requires an unshielded twisted-pair (UTP) cable with RJ-45 connectors at both
ends. Use Category 5, 5e or 6 cable for 1000BASE-T connections, Category 5 or better for
100BASE-TX connections.
Cabling Guidelines
The RJ-45 ports on the switch support automatic MDI/MDI-X pinout configuration, so you can
use standard straight-through twisted-pair cables to connect to any other network device
(PCs, servers, switches, routers, or hubs). See Appendix B for further information on cabling.
CAUTION: Do not plug a phone jack connector into an RJ-45 port. This will damage
the switch. Use only twisted-pair cables with RJ-45 connectors that conform to FCC standards.

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Connecting to PCs, Servers, Hubs and Switches
Step 1. Attach one end of a twisted-pair cable segment to the device’s RJ-45 connector.
Step 2. If the device is a network card and the switch is in the wiring closet, attach the other
end of the cable segment to a modular wall outlet connected to the wiring closet. See the
section “Network Wiring Connections”. Otherwise, attach the other end to an available port
on the switch. Make sure each twisted pair cable does not exceed 100 meters (328 ft) long
NOTE: Avoid using flow control on a port connected to a hub unless it is actually
required to solve a problem. Otherwise back pressure jamming signals may degrade overall
performance for the segment attached to the hub.
Step 3. As each connection is made, the switch Link LED corresponding to each port will light
green (1000 Mbps) or amber (100 Mbps) to indicate the connection is valid.
Network Wiring Connections
The punch-down block is an integral part of many of the newer equipment racks. It is actually
part of the patch panel. Instructions for making connections in the wiring closet with this type
of equipment follows.
Step 1. Attach one end of a patch cable to an available port on the switch, and the other end
to the patch panel.
Step 2. If not already in place, attach one end of a cable segment to the back of the patch
panel where the punch-down block is located, and the other end to a modular wall outlet.
Step 3. Label the cables to simplify future troubleshooting. See “Cable Labeling and
Connection Records” on page 29.
Switch
Equipment Rack
(side view)
Patch Panel
Patch-Down Block
Wall

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Fiber Optic SFP
An optional Gigabit SFP transceiver can be used for a backbone connection between switches,
or for connecting to a high-speed server.
Each single-mode fiber port requires 9/125 micron single-mode fiber optic cable with an LC
connector at both ends. Each multimode fiber optic port requires 50/125 or 62.5/125 micron
multimode fiber optic cabling with an LC connector at both ends.
WARNING: This switch uses lasers to transmit signals over fiber optic cable. The lasers
are inherently eye safe in normal operation. However, user should never look directly at a
transmit port when it is powered on.
WARNING: When selecting a fiber SFP device, considering safety, please make sure that
it can function at a temperature that is not less than the recommended maximum operational
temperature of the product. You must also use an approved Laser SFP transceiver.
Step 1. Remove and keep the LC port’s rubber plug. When not connected to a fiber cable, the
rubber plug should be replaced to protect the optics.
Step 2. Check that the fiber terminators are clean. You can clean the cable plugs by wiping
them gently with a clean tissue or cotton ball moistened with a little ethanol. Dirty fiber
terminators on fiber optic cables will impair the quality of the light transmitted through the
cable and lead to degraded performance on the port.
Step 3. Connect one end of the cable to the LC port on the switch and the other end to the LC
port on the other device. Since LC connectors are keyed, the cable can be attached in only one
orientation. Damage may occur if forced in the wrong orientation.
Step 4. As a connection is made, check the Link LED on the switch corresponding to the port
to be sure that the connection is valid.

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1000BASE-T Cable Requirements
When adding hubs to your network, please note that because switches break up the path for
connected devices into separate collision domains, you should not include the switch or
connected cabling in your calculations for cascade length involving other devices.
All Category 5 UTP cables that are used for 100BASE-TX connections should also work for
1000BASE-T, providing that all four wire pairs are connected. However, it is recommended
that for all critical connections, or any new cable installations, Category 5e or Category 6
cable should be used. The Category 5e and 6 specifications include test parameters that are
only recommendations for Category 5. Therefore, the first step in preparing existing Category
5 cabling for running 1000BASE-T is a simple test of the cable installation to be sure that it
complies with the IEEE 802.3-2005 standards
Cable Labeling and Connection Records
When planning a network installation, it is essential to label the opposing ends of cables and
to record where each cable is connected. This will allow user to easily locate inter-connected
devices, isolate faults and change your topology without need for unnecessary time
consumption.
To best manage the physical implementations of your network, follow these guidelines:
• Clearly label the opposing ends of each cable.
• Using your building’s floor plans, draw a map of the location of all network-
connected equipment. For each piece of equipment, identify the devices to which it
is connected.
• Note the length of each cable and the maximum cable length supported by the
switch ports.
• For ease of understanding, use a location-based key when assigning prefixes to your
cable labeling.
• Use sequential numbers for cables that originate from the same equipment.
• Differentiate between racks by naming accordingly.
• Label each separate piece of equipment.
• Display a copy of your equipment map, including keys to all abbreviations at each
equipment rack.

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Troubleshooting
Most problems are caused by the following situations. Check for these items first when
starting your troubleshooting.
Basic Troubleshooting Tips
Connecting to devices that have a fixed full- duplex configuration.
The RJ-45 ports are configured as “Auto”. That is, when connecting to attached devices, the
switch will operate in one of two ways to determine the link speed and the communication
mode (half duplex or full duplex):
•If the connected device is also configured to Auto, the switch will automatically
negotiate both link speed and communication mode.
•If the connected device has a fixed configuration, for example 100Mbps, at half or
full duplex, the switch will automatically sense the link speed, but will default to a
communication mode of half duplex.
Because the SM24T6DPA behaves this way (in compliance with the IEEE802.3 standard), if a
device connected to the switch has a fixed configuration at full duplex, the device will not
connect correctly to the switch. The result will be high error rates and very inefficient
communications between the switch and the device.
Make sure all devices connected to the SM24T6DPA are configured to auto negotiate or are
configured to connect at half duplex (all hubs are configured this way, for example).
Faulty or loose cables. Look for loose or obviously faulty connections. If they appear to be
OK, make sure the connections are snug. If that does not correct the problem, try a different
cable.
Non-standard cables. Non-standard and miswired cables may cause network collisions and
other network problems and can seriously impair network performance. Use a new
correctly-wired cable. For pinouts and correct cable wiring. A category 5 cable tester is a
recommended tool for every 100Base-TX and 1000Base-T network installation.
Improper Network Topologies. It is important to make sure you have a valid network
topology. If you no longer experience the problems, the new topology is probably at fault. In
addition, you should make sure that your network topology contains no data path loops
Check the port configuration.
A port on the switch may not be operating as you expect because it has been put into a
“ blocking” state by Spanning Tree, GVRP (automatic VLANs), or LACP (automatic trunking).
(Note that the normal operation of the Spanning Tree, GVRP, and LACP features may put the
port in a blocking state.) Or the port just may have been configured as disabled through
software.

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Troubleshooting Chart
Symptom
Action
POWER LED is Off
1. Check connections between the switch, the power cord and the
wall outlet.
2. Contact your dealer for assistance.
Link LED is Off
1. Verify that the switch and attached device are powered on.
2. Be sure the cable is plugged into the switch and corresponding
device.
3. If the switch is installed in a rack, check the connections to the
punch-down block and patch panel.
4. Verify that the proper cable type is used, and its length does not
exceed specified limits.
5. Check the adapter on the attached device and cable connections
for possible defects. Replace the defective adapter or cable if
necessary.
Troubleshooting Power and Cooling Problems
Installation
If the power indicator does not turn on when the power cord is plugged in, you may have a
problem with the power outlet, power cord, or internal power supply. However, if the unit
powers off after running for a while, check for loose power connections, power losses or
surges at the power outlet. If you still cannot isolate the problem, the internal power supply
may be defective. Verify that all system components have been properly installed. If one or
more components appear to be malfunctioning (such as the power cord or network cabling),
test them in an alternate environment where you are sure that all the other components are
functioning properly.
In-Band Access
You can access the management agent in the switch from anywhere within the attached
network using Telnet or a web browser. However, you must first configure the switch with a
valid IP address, subnet mask, and default gateway. If you have trouble establishing a link to
the management agent, check to see if you have a valid network connection. Then verify
that you entered the correct IP address. Also, be sure the port through which you are
connecting to the switch has not been disabled. If it has not been disabled, then check the
network cabling that runs between your remote location and the switch.
NOTE: The management agent accepts up to four simultaneous Telnet sessions. If the
maximum number of sessions already exists, an additional Telnet connection will not be able
to log into the system.