WiFi mesh with NETGEAR D7800

This is a step-by-step guide to setting up a 2-node WiFi mesh with 2 NETGEAR NIGHTHAWK X4S D7800 AC2600 routers using OpenWrt, with an Ethernet backbone.

It’s important to note that while the D7800 is a fantastic router, creating a true, seamless mesh with automatic client steering (like what dedicated mesh systems offer) using OpenWrt on this hardware for this specific model can be complex and might not yield the same “out-of-the-box” experience as a purpose-built mesh system. However, we can achieve a functional roaming setup using multiple access points with the same SSID and password, which is often what users mean by “mesh” in a practical sense for their home networks. This guide focuses on that.

Advanced Roaming: More managed roaming experience can be achieved with technologies like 802.11r (Fast BSS Transition) and 802.11k/v but is not covered in this post.

Important Considerations Before You Start

Risk of Bricking: Flashing custom firmware always carries a risk of bricking your device. Follow instructions carefully.
Warranty: Installing OpenWrt will likely void your router’s warranty.
Current Date: As of June 2025, OpenWrt officially supports the D7800. Ensure you download the latest stable build.
Backup: If you have any critical configurations on your current router’s firmware, back them up.

Step-by-Step Guide to OpenWrt Mesh Setup

1. Download OpenWrt Firmware

You’ll need the correct OpenWrt firmware image for your NETGEAR NIGHTHAWK X4S D7800.

Go to the official OpenWrt website: https://openwrt.org/
Navigate to the “Table of Hardware” or search for “NETGEAR D7800”.
Look for the “Factory” image for your first installation. This is typically a .img or .chk file designed to be flashed from the stock Netgear firmware. For subsequent upgrades or if you’re already on OpenWrt, you’d use the “Sysupgrade” image.
Download the latest stable release of OpenWrt for your D7800.
- Filename Example (may vary slightly with new releases): openwrt-[version]-ipq806x-generic-netgear_d7800-squashfs-factory.img

2. Install OpenWrt on Your First Router (Router A)

This is the most critical step. Take your time.

Connect Router A:
- Disconnect Router A from your main internet connection.
- Connect your computer directly to one of Router A’s LAN ports using an Ethernet cable.
- Ensure no other devices are connected to Router A.
Access Stock Firmware:
- Open a web browser and go to your router’s default IP address (usually 192.168.1.1 or 192.168.0.1).
- Log in with your administrator credentials.
Find Firmware Upgrade Section:
- Look for an “Administration,” “Firmware Upgrade,” “Router Upgrade,” or “Advanced” section in the stock Netgear firmware interface.
Upload OpenWrt Firmware:
- Select the “Factory” image you downloaded earlier.
- Crucial: Double-check that you’re uploading the correct file for the D7800. Uploading the wrong firmware can brick your device.
- Initiate the upgrade process. DO NOT INTERRUPT THE PROCESS. The router will reboot multiple times. This can take several minutes.
Verify OpenWrt Installation:
- After the router reboots, your computer might lose connection.
- Try to access 192.168.1.1 in your browser. This is the default IP for OpenWrt.
- You should see the LuCI web interface for OpenWrt.
- The first time you access it, it will prompt you to set a root password. Set a strong password.

3. Configure Router A (Main Access Point)

Router A will act as your primary access point. Since you don’t need routing, we’ll focus on the network and wireless configuration.

Log in to LuCI:
- Access 192.168.1.1 in your web browser and log in with the root password you just set.
Network Configuration:
- Go to Network > Interfaces.
- You’ll see LAN (bridged to your Ethernet ports and Wi-Fi) and WAN.
- Modify LAN Interface:
  - Click “Edit” next to the LAN interface.
  - Change the IPv4 address to something outside the range of your main network’s DHCP server, or a static IP you want for Router A (e.g., 192.168.1.254 if your main network is 192.168.1.x). This is important if you want to access LuCI later without IP conflicts.
  - Disable DHCP Server: Under the “DHCP Server” tab, uncheck “Enable DHCP for this interface.” Since your main network will handle DHCP, you don’t want your APs also handing out IPs.
  - Click “Save” and then “Save & Apply.” Your browser connection might drop. Reconnect using the new IP if you changed it.
- Disable WAN Interface:
  - Go to Network > Interfaces.
  - Click “Edit” next to the WAN interface.
  - Under the “General Setup” tab, change the “Protocol” to “Unmanaged.”
  - Click “Save” and then “Save & Apply.”
Wireless Configuration:
- Go to Network > Wireless.
- You’ll see two radio interfaces: radio0 (2.4GHz) and radio1 (5GHz).
- For both radio0 and radio1:
  - Click “Edit” next to each.
  - Enable the interface if it’s disabled.
  - Set the Mode to “Access Point.”
  - Set the ESSID (Wi-Fi name) to your desired network name (e.g., MyHomeWiFi).
  - Set the Encryption to “WPA2-PSK” (or WPA3 if your devices support it and you prefer it).
  - Enter a strong Key (Wi-Fi password). This MUST be identical on both routers for seamless roaming.
  - Optional (but recommended): Select a non-overlapping channel for 2.4GHz (1, 6, or 11). For 5GHz, you have more options, but avoid DFS channels if you experience issues.
  - Click “Save” and then “Save & Apply.”

4. Install OpenWrt on Your Second Router (Router B)

Repeat Step 2 (Install OpenWrt) for your second router (Router B). The process is identical.

5. Configure Router B (Second Access Point)

Router B will be your second access point. The configuration is very similar to Router A, with key differences in IP address and DHCP.

Log in to LuCI:
- Access 192.168.1.1 in your web browser (after flashing, it will default back to this IP) and log in with the root password you set.
Network Configuration:
- Go to Network > Interfaces.
- Modify LAN Interface:
  - Click “Edit” next to the LAN interface.
  - Change the IPv4 address to a different static IP address within the same subnet as Router A, but distinct from your main network’s router and Router A (e.g., 192.168.1.253). This allows you to access Router B’s LuCI interface later.
  - Disable DHCP Server: Under the “DHCP Server” tab, uncheck “Enable DHCP for this interface.”
  - Click “Save” and then “Save & Apply.”
- Disable WAN Interface:
  - Go to Network > Interfaces.
  - Click “Edit” next to the WAN interface.
  - Under the “General Setup” tab, change the “Protocol” to “Unmanaged.”
  - Click “Save” and then “Save & Apply.”
Wireless Configuration:
- Go to Network > Wireless.
- For both radio0 and radio1:
  - Click “Edit” next to each.
  - Enable the interface if it’s disabled.
  - Set the Mode to “Access Point.”
  - Set the ESSID (Wi-Fi name) to the EXACT SAME name as you used on Router A (e.g., MyHomeWiFi).
  - Set the Encryption to “WPA2-PSK” (or WPA3).
  - Enter the EXACT SAME Key (Wi-Fi password) as you used on Router A.
  - Optional (but recommended): Select a non-overlapping channel for 2.4GHz (if Router A is on 1, use 6 or 11 for Router B). For 5GHz, try to select a different non-overlapping channel if possible, or use the same channel if range is your priority (but this can increase interference).
  - Click “Save” and then “Save & Apply.”

6. Connect Your Mesh Nodes via Ethernet Backbone

Connect Router A to Main Network:
- Connect one of Router A’s LAN ports to your main network’s router (or switch).
Connect Router B to Main Network:
- Connect one of Router B’s LAN ports to your main network’s router (or switch).

This creates your Ethernet backbone. Since the DHCP server on both D7800s is disabled, your main router will handle IP address assignment for all devices.

7. Testing Your Roaming Mesh

Connect Devices:
- Connect your Wi-Fi devices (smartphone, laptop, etc.) to your MyHomeWiFi network.
Walk Around:
- Start near Router A and then walk towards Router B while continuously pinging a reliable internet address (e.g., ping google.com) or streaming video.
- Your device should seamlessly roam between the two access points without dropping the connection. The handover isn’t instantaneous but should be quick enough for most applications.

Troubleshooting Tips

Can’t access LuCI:
- Ensure your computer’s IP address is in the same subnet as the router (e.g., if the router is 192.168.1.1, your computer should be 192.168.1.x where x is not 1).
- Try clearing your browser’s cache.
- If you changed the router’s IP and forgot it, you might need to factory reset OpenWrt (usually by holding the reset button for 10-15 seconds while powered on).
No Internet:
- Double-check that the DHCP server is disabled on both OpenWrt routers.
- Verify that your main network router is functioning correctly and providing DHCP.
- Ensure the Ethernet backbone connections are solid.
Poor Roaming:
- Signal Overlap: Ensure there’s a good overlap in signal between the two access points without being too strong in the middle. Adjust placement.
- Channel Interference: While using the same SSID and password is key, having different non-overlapping channels (especially on 2.4GHz) can reduce interference.
- Client Behavior: Roaming performance is largely dependent on the client device (phone, laptop). Some devices are better at roaming than others.
- Advanced Roaming (Optional): For a more managed roaming experience, you could explore technologies like 802.11r (Fast BSS Transition) and 802.11k/v. However, these require more advanced OpenWrt configuration and client support, and are often more complex than necessary for a simple home setup. The D7800 also has limitations regarding some advanced mesh features.

This setup provides a robust and performant roaming Wi-Fi network using your D7800s as powerful access points with an Ethernet backbone. Enjoy your extended Wi-Fi coverage!