NETGEAR CMD31T Installation Manual Download Page 2

September 2011

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Electrical and Electronic Equipment (the WEEE Directive). If disposed of within the European Union, 
this product should be treated and recycled in accordance with the laws of your jurisdiction 
implementing the WEEE Directive.

©2011 by NETGEAR, Inc. All rights reserved. NETGEAR and the NETGEAR logo are registered trademarks of 
NETGEAR, Inc. in the United States and/or other countries. Other brand and product names are trademarks or 
registered trademarks of their respective holders. Information is subject to change without notice. 

LEDs

Power 

Solid green

: Power is on.

Off

: Power is off.

Online 

(Cable Link) 

Green blinking

: The cable modem is on-line and processing 

traffic.

Off

: The cable modem is off line.

US (Upstream)

1/2 solid amber

: Upstream Channel 1 is in use.

1/2 solid green

: Upstream Channels 1 and 2 are in use.

3/4 solid amber

: Upstream Channels 1, 2, and 3 are in use.

3/4 solid green

: Upstream Channels 1, 2, 3, and 4 are in use.

Off

: No upstream channel is in use.

DS (Downstream)

1/2 solid amber

: Downstream Channel 1 is in use.

1/2 solid green

: Downstream Channels 1 and 2 are in use.

3/4 solid amber

: Downstream Channels 1, 2, and 3 are in use.

3/4 solid green

: Downstream Channels 1, 2, 3, and 4 are in use.

Off

: No downstream channel is in use.

Ethernet 

Solid green

: A 1 Gbps device is connected and detected on the 

Ethernet port.

Solid Amber

: A 100 Mbps device is connected and detected on 

the Ethernet port.

Solid Red

: A 10 Mbps device is connected and detected on the 

Ethernet port.

Blinking

: There is data traffic on the Ethernet port.

Off

: No device is detected on the Ethernet port.

Troubleshooting

No LEDs are lit 
on the cable 
modem

The cable modem has no power. Make sure that:

• The power adapter is correctly connected to the cable modem.

• The power adapter is correctly connected to a functioning power 

outlet. If it is to a power strip, make sure the power strip is turned on.

• You are using the correct power adapter.

Online LED 
does not light 
up

There is a hardware connection problem, or you do not have cable 
service. Do the following:

• Make sure the cable connector is securely plugged in at the cable 

modem.

• Turn the power to the cable modem off and on.

• You might not have active cable service yet. Contact your provider to 

verify activation.

Ethernet LED 
does not light 
up even though 
a device is 
attached

There is a hardware connection problem. Do the following:

• Make sure the cable connector is securely plugged in to the cable 

modem and the computer.

• If you are not using the cable included with the cable modem, check 

that the Ethernet cable is a straight-through patch cable.

You cannot 
connect to the 
Internet

It can take up to 15 minutes to establish a connection the first time you 
power on your cable modem. Always leave your cable modem plugged 
in to AC power and connected to the cable system. Do the following:

• Check your cable connections. Connectors should be finger tight.

• Make sure that you have powered up in the following sequence:

-  Turn on your cable modem first, and wait until the LEDs stop 

flashing.

-  If your computer is connected to the cable modem, turn on the 

computer.

• If you have a home network, check the TCP/IP configuration.

-  For Windows, the network properties should be set to obtain an IP 

address automatically.

-  For Macintosh computers, the TCP/IP (or Network) control panel 

should be set to Using DHCP Server.

Technical Support

Thank you for selecting NETGEAR products. 

After installing your device, locate the serial number on the label of your product and 
use it to register your product at 

www.netgear.com/register. 

Registration is required 

before you can use the telephone support service. Registration through the 
NETGEAR website is strongly recommended.

Go to 

support.netgear.com 

for product updates and web support

NETGEAR technical support: 1-888-638-4327, for US and Canada only.

For complete DoC please visit the NETGEAR EU Declarations of Conformity 
website at: 

support.netgear.com/app/answers/detail/a_id/11621/

.

For GNU General Public License (GPL) related information, go to 

support.netgear.com/app/answers/detail/a_id/2649

.

WARNING!!   

DO 

not

 stack equipment, or place equipment in tight spaces or in drawers. Be 

sure your equipment is surrounded by at least 2 inches of air space. 

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