Netgear Cm400 High Speed Cable Modem Docsis 3 0 User Manual

350 East Plumeria Drive
San Jose, CA 95134 
USAJuly 2015
202-11412-02
CM400 High Speed Cable Modem
User Manual 

 
2 CM400 High Speed Cable Modem 
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 https://my.netgear.com. You must register your product before you can use NETGEAR telephone support. NETGEAR recommends registering your product through the NETGEAR website. 
For product updates and web support, visit http://support.netgear.com.
Phone (US & Canada only): 1-888-NETGEAR.
Phone (Other...

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Contents
Chapter 1 Hardware and Internet Setup
Unpack Your Cable Modem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  5
Front Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Back Panel. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Product Label . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ....

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1
1.   Hardware and Internet Setup
The NETGEAR CM400 High Speed Cable Modem provides a connection to high-speed cable 
Internet with speeds up to 340 Mbps.1 The cable modem is certified by all major cable Internet 
providers. A Gigabit Ethernet port provides fast access and downloads. The cable modem 
supports IPv4 and IPv6 address assignment by cable Internet providers.
This chapter covers the following topics:
•Unpack Your Cable Modem
•Front Panel
•Back Panel
•Product Label
•Attach the Feet
•Cable...

Hardware and Internet Setup 5
 CM400 High Speed Cable Modem
Unpack Your Cable Modem
Your package contains the following items.
Ethernet cable
Power adapter
Cable modem
Attachable feet
Figure 1. Package contents
Front Panel
The 
cable modem  provides status LEDs on the front.
Power LED
Downstream LED Upstream LED
Internet LEDEthernet LED
Figure 2. Cable modem front view 

Hardware and Internet Setup 6
CM400 High Speed Cable Modem 
You can use the LEDs to verify status and connections. The following table lists and 
describes each LED on the front panel of the cable modem.
Table 1.  LED descriptions  
LEDDescription
Power 
•  Green. Power is supplied to the cable modem.
•  Off. No power is supplied to the cable modem.
Downstream 
•  Solid amber . One downstream channel is locked.
•  Solid green . T
 wo or more downstream channels are locked.
•  Blinking green . The 
 cable...

Hardware and Internet Setup 7
 CM400 High Speed Cable Modem
Product Label
The product label on the bottom of the cable modem displays the serial n\
umber and MAC 
address of the cable modem and login information, including the default \
IP address, 
default user name, and default password.
Figure 4.  Product label
Attach the Feet
The cable modem functions well in either a horizontal or vertical positi\
on.
If you prefer to place the cable modem in the upright (vertical) posit\
ion, attach the feet that...

Hardware and Internet Setup 8
CM400 High Speed Cable Modem 
Cable Your Cable Modem
The cable modem provides a connection between your cable Internet provid\
er’s network and 
your computer, router, or WiFi router.
Computer, 
router, or 
WiFi router
Cable modem
Coaxial cable to cable outlet Ethernet
cable
Figure 6. Cabling the cable modem

To cable your cable modem:
1.  Connect a coaxial cable.
Use the coaxial cable that your cable company provides to connect the ca\
ble port on the 
cable 
 modem to a...

Hardware and Internet Setup 9
 CM400 High Speed Cable Modem
5. 
Turn on the computer, router, or WiFi router.
6.  W
ait for the cable modem to come online.
It takes at least 15 minutes for the cable modem to come online on the n\
etwork. During 
this time, the Downstream LED 
 and Upstream LED  might blink.
After the cable modem  registers with your cable Internet service provider
 , the 
Internet
  LED 
 lights green. Even though an Internet connection is established, 
Internet service is available only...

Hardware and Internet Setup 
10 CM400 High Speed Cable Modem 
Note:The contact information listed might change. You can also find the 
contact number in your monthly Internet service billing statement.
2. When asked, provide the cable modem’s serial number and MAC address, which are on the 
product label (see 
Product Label on page 7).
3. Wait for your cable Internet provider to confirm that your cable modem is active.
4. If you do not get an Internet connection with the cable modem, ask your cable...