Netgear D6400 – AC1600 WiFi VDSL/ADSL Modem Router—802.11ac Dual Band Gigabit User Manual

The following table includes tips for troubleshooting some common problems. 

Your network is unresponsive 
or does not function normally.

Restart your network:

Turn off and unplug the DSL, cable, or fiber modem.

Turn off the modem router.

Plug in the DSL, cable, or fiber modem and turn it on. Wait two minutes.

Turn on the modem router and wait two minutes.

If network problems still occur, make sure that your ISP does not require you to 
use the MAC address of the computer that was used to initially register the ISP 
account. If your ISP does require that you do this, you must change the modem 
router MAC address that the modem router uses. For more information, see 
one of the following sections:

•  Manually Set Up an ADSL Internet Connection 

•  Manually Set Up a VDSL Internet Connection 

•  Manually Set Up a Cable of Fiber Internet Connection 

Your cannot connect over an 
Ethernet cable to the modem 
router.

Make sure that the Ethernet cables are securely plugged in.

Make sure that your computer or device does not use a static IP address 
but is configured to receive an IP address automatically with DHCP. (For 
most devices, DHCP is the default setting.)

You cannot connect over WiFi 
to the modem router.

Make sure that the WiFi settings in your WiFi device and modem router 
match exactly.
For a device that is connected over WiFi, the WiFi network name (SSID) 
and WiFi security settings of the modem router and WiFi computer must 
match exactly. The default SSID and password are on the product label (see 

Make sure that your WiFi device supports the security that you are using 
for your WiFi network (WEP, WPA, or WPA2). For information about WiFi 
security settings, see 

Make sure that the modem router is not too far from your WiFi device or too 
close:

Move your WiFi device near the modem router but at least 6 feet 
(1.8

 

meters) away and see if the signal strength improves.

Make sure that the WiFi signal is not blocked by objects between the 
modem router and your WiFi device.

Make sure that the WiFi LED on the modem router is not off.
If this LED is off, both WiFi radios might be disabled. For more information 
about the WiFi radios, see 

 110.