1. Product Overview
The NETGEAR Nighthawk C7800 is an ultra-high-speed cable modem router designed to deliver fast internet speeds and robust WiFi performance. It combines a DOCSIS 3.1 cable modem with an AC3200 WiFi router, making it suitable for high-bandwidth activities like 4K streaming and online gaming. This device eliminates the need for separate modem and router units, potentially saving on equipment rental fees.

Figure 1: Front view of the NETGEAR Nighthawk C7800 Cable Modem Router, showcasing its sleek design and four external antennas.
2. Package Contents
Ensure all items are present in your package:
- Nighthawk X4S AC3200 WiFi Cable Modem Router (C7800)
- Ethernet cable
- Quick Start Guide
- Power adapter

Figure 2: The retail packaging for the NETGEAR Nighthawk C7800, indicating its model and key features.
3. Setup Instructions
Follow these steps to set up your NETGEAR Nighthawk C7800 cable modem router:
- Connect the Coaxial Cable: Connect a coaxial cable from your cable wall outlet to the Cable port on the back of the modem router. Ensure the connection is secure.
- Connect the Power Adapter: Plug the power adapter into the modem router and then into a power outlet. Wait for the Power LED on the front of the modem router to turn solid white.
- Activate Your Internet Service: Contact your Internet Service Provider (ISP) to activate your internet service. You will need the modem router's serial number and MAC address, usually found on a label on the device.
- Connect Your Devices: Once activated, you can connect devices via Ethernet cable to the Gigabit Ethernet ports or wirelessly using the WiFi network name (SSID) and password found on the product label.

Figure 3: Rear view of the C7800, showing the Cable input, four Gigabit Ethernet ports, and Power On/Off button. Note the two USB 3.0 ports on the side (not visible in this image).
Video 1: An official overview of the NETGEAR C7800 Modem, highlighting its features and capabilities.
4. Operating Instructions
Once your modem router is set up and internet service is active, it will automatically broadcast WiFi networks. You can manage your network settings through the NETGEAR Genie interface by accessing routerlogin.net or 192.168.0.1 from a connected web browser.
4.1 Connecting Devices
- Wireless Connection: Search for the WiFi network name (SSID) on your device and enter the password. The default SSID and password are on the product label.
- Wired Connection: Use an Ethernet cable to connect your computer, gaming console, or other network devices to one of the four Gigabit Ethernet ports on the back of the modem router.
4.2 USB Storage
The C7800 features two USB 3.0 ports for connecting external storage devices. You can share files across your network or access them remotely using NETGEAR ReadySHARE.
5. Maintenance
To ensure optimal performance and longevity of your NETGEAR Nighthawk C7800:
- Firmware Updates: Regularly check for and install firmware updates through the NETGEAR Genie interface. Updates often include performance improvements and security patches.
- Placement: Place the modem router in a central location, away from obstructions and other electronic devices that might cause interference.
- Cleaning: Keep the device clean and free from dust to prevent overheating. Use a soft, dry cloth for cleaning.
- Restart: Periodically restart the modem router (unplug from power for 10 seconds, then plug back in) to refresh its connection and clear any temporary issues.
6. Troubleshooting
6.1 No Internet Connection
- Check all cable connections, especially the coaxial cable to the wall outlet and the power adapter.
- Verify that your internet service is active with your ISP.
- Restart the modem router and your connected devices.
6.2 Slow WiFi Speed
- Ensure the modem router is placed optimally, away from interference.
- Check for firmware updates.
- Reduce the number of devices connected to the network or consider using the 5GHz band for faster speeds on compatible devices.
6.3 Cannot Access Router Settings
- Ensure your device is connected to the modem router's network (either wired or wirelessly).
- Try accessing routerlogin.net or 192.168.0.1 in your web browser.
- If you have changed the login credentials and forgotten them, you may need to perform a factory reset (refer to the Quick Start Guide for instructions).
7. Technical Specifications
| Feature | Specification |
|---|---|
| Model Name | C7800-100NAS |
| Wireless Type | 802.11ac (AC3200) |
| DOCSIS Standard | DOCSIS 3.1 (backward compatible with DOCSIS 3.0) |
| Ethernet Ports | 4 Gigabit Ethernet ports |
| USB Ports | 2 USB 3.0 ports |
| Processor | Powerful dual-core 1.5GHz processor |
| Dimensions (LxWxH) | 10.4 x 7.5 x 12.4 inches |
| Item Weight | 3.15 pounds |
| Operating System | NETGEAR firmware (based on Linux) |
8. Warranty and Support
NETGEAR products typically come with a limited hardware warranty. For specific warranty details, registration, and technical support, please visit the official NETGEAR support website or refer to the warranty card included in your product packaging. You can also find FAQs and community forums for assistance.
Online Support: www.netgear.com/support