User Manual Nighthawk AC1900 WiFi Cable Modem Router Model C6900 NETGEAR, Inc. February 2021 350 East Plumeria Drive 202-12222-01 San Jose, CA 95134, USA Nighthawk AC1900 WiFi Cable Modem Router Support and Community Visit netgear.com/support to get your questions answered and access the latest downloads. You can also check out our NETGEAR Community for helpful advice at community.netgear.com. Customer-owned cable devices might not be compatible with certain cable networks. Check with your cable Internet provider to confirm that this NETGEAR cable device is allowed on your cable network. If you are experiencing trouble installing your cable device, contact NETGEAR at 1-866-874-8924. Note to CATV system installer: This reminder is provided to call the CATV systems installer’s attention to Section 820-93 of the National Electrical Code, which provide guidelines for proper grounding and in particular, specify that coaxial cable shield shall be connected to the grounding system of the building, as close to the point of cable entry as practical. Regulatory and Legal Si ce produit est vendu au Canada, vous pouvez accéder à ce document en français canadien à https://www.netgear.com/support/download/. (If this product is sold in Canada, you can access this document in Canadian French at https://www.netgear.com/support/download/.) For regulatory compliance information including the EU Declaration of Conformity, visit https://www.netgear.com/about/regulatory/. See the regulatory compliance document before connecting the power supply. For NETGEAR’s Privacy Policy, visit https://www.netgear.com/about/privacy-policy. By using this device, you are agreeing to NETGEAR’s Terms and Conditions at https://www.netgear.com/about/terms-and-conditions. If you do not agree, return the device to your place of purchase within your return period. Trademarks ©NETGEAR, Inc. NETGEAR and the NETGEAR Logo are trademarks of NETGEAR. 2 User Manual Contents Chapter 1 Hardware Setup Unpack Your Modem Router. 8 Front Panel. 9 Rear Panel . 11 Position Your Modem Router . 11 Cable Your Modem Router. 12 Cable the Modem Router in a Simple Network . .13 Cable Your Modem Router to a Router and Use Bridge Mode. .13 Activate Your Internet Service. 15 Activate Your Internet Service With Comcast Xfinity . 16 Chapter 2 Connect to the Network and Access the Modem Router Connect to the Network . .19 Wired Connection. .19 WiFi Connection . .19 Label . .20 Types of Logins . 20 Log In to the Modem Router . 20 Access the Modem Router with NETGEAR genie App . 22 Chapter 3 Specify Your Internet Settings Specify the Cable Connection Starting Frequency . .24 View Modem Router Initialization . 25 Manually Set Up the Internet Connection . 26 Specify an IPv6 Internet Connection . 27 Change the MTU Size . 28 Chapter 4 Control Access to the Internet Block Access to Your Network . 31 Use Keywords to Block Internet Sites . 32 Block Services from the Internet. 34 Schedule When to Block Internet Sites and Services . 35 Avoid Blocking on a Trusted Computer . 36 Set Up Security Event Email Notifications. 37 Chapter 5 Specify Network Settings View WAN Settings . .40 4 Nighthawk AC1900 WiFi Cable Modem Router Set Up a Default DMZ Server . 41 Change the Modem Router’s Device Name . 42 Change the LAN TCP/IP Settings. 42 Specify the IP Addresses that the Modem Router Assigns . 44 Disable the DHCP Server Feature in the Modem Router. 45 Reserve LAN IP Addresses . 46 Improve Network Connections with Universal Plug and Play . 47 Use the WPS Wizard for WiFi Connections . 48 Specify Basic WiFi Settings . 49 Change the WiFi Security Option . 51 Set Up a Guest Network . 52 Control the Wireless Radios . 54 Use the WiFi On/Off Button. .54 Enable or Disable the Wireless Radios . .54 Set Up a Wireless Schedule . 55 Specify WPS Settings . 56 Chapter 6 Manage Your Network Change the admin Password. .59 View Modem Router Status. 59 Display Internet Port Statistics . .60 Check the Internet Connection Status . .61 View Logs of Modem Router Activity. 62 View Event Logs. .64 Run the Ping Utility . .65 Run the Traceroute Utility . 66 Monitor Internet Traffic . 67 View Devices Currently on the Network . 68 Manage the Modem Router Configuration File . 69 Back Up Settings . .69 Restore Configuration Settings . .70 Erase the Current Configuration Settings . .71 View Wireless Access Points in Your Area . 71 View or Change the Modem Router Wireless Channel . 72 Dynamic DNS . 73 Specify a DNS Account. .74 Change the Dynamic DNS Settings . .74 Remote Management . 75 Chapter 7 Specify Internet Port Settings Set Up Port Forwarding to a Local Server . .78 Add a Custom Port Forwarding Service . .79 Edit a Port Forwarding Service . .80 Delete a Port Forwarding Entry. .81 Application Example: Make a Local Web Server Public . .81 How the Modem Router Implements the Port Forwarding Rule . .81 Set Up Port Triggering. 82 5 User Manual Nighthawk AC1900 WiFi Cable Modem Router Add a Port Triggering Service. .83 Application Example: Port Triggering for Internet Relay Chat . .84 Chapter 8 Troubleshooting Troubleshoot with the LEDs. .86 Power LED Is Off . .86 LEDs Never Turn Off . .86 Internet LED Is Off . .86 Troubleshoot the Cable Internet Connection . 87 Cannot Log In to the Modem Router . 87 Changes Not Saved . .89 Wireless Connectivity. 89 Troubleshoot Your Network Using the Ping Utility . 90 Test the LAN Path to Your Modem Router . .90 Test the Path from Your Computer to a Remote Device. ..