FiOS & Deco Mesh Fix

I have Verizon FiOS and recently updated my mesh router to a Deco BE 1000. I started having issues with my Sonos system right after setting up the new Deco, and suspected the "double NAT" issue was the problem. Unfortunately, I can't put the FiOS router into bridge mode because it also is my cable provider and apparently bridge mode would mess that up. I also did not want to set up the new routers as access points and lose some of the features I paid for. So I turned to Google Gemini for help. Gemini's solution was to enable the "DMZ Host" feature in the FiOS router. Gemini said this would "effectively bypass the first layer of NAT for your mesh system, resolving most issues that Double NAT causes." Don't ask me to really explain what that means. However, I followed the step by step instructions to enable the DMZ Host feature, and my Sonos system immediately become much more reliable. I've still had some glitches, but a fraction of the issues I had before this change, and it seems to be improving as time passes.

Given my success with this change, I thought I would pass along the steps Gemini gave me for anyone who may be looking for a similar solution.

It sounds like you're setting up a mesh router behind your FiOS router and want to use the DMZ feature. You only need to set a static equivalent for the IPv4 address on the mesh router's WAN port, as the IPv6 process is typically automatic and hidden. Here is the step-by-step process, performed entirely on your FiOS Router, to set a static IPv4 address using a DHCP Reservation and then enable the DMZ.

Step 1: Find the Mesh Router's WAN MAC Address Before starting, you need the unique identifier of the device you are putting in the DMZ.

• Locate the Address: Get the WAN MAC Address of your mesh router (this is the physical address of the port that plugs into the FiOS router).
  • Tip: This is often available in your mesh router's mobile app or web interface, usually under WAN Status or Internet Connection Details. Alternatively, it will be listed in the Connected Devices list on your FiOS router's interface.

Step 2: Create an IPv4 DHCP Reservation (Static Equivalent) A DHCP Reservation is the proper way to assign a permanent IP address to a device that is configured to use DHCP (like your mesh router).

• Access FiOS Router Settings: Log into your FiOS router's web interface (usually by navigating to its gateway IP, like 192.168.1.1).
• Navigate to DHCP Settings: Look for the section titled Advanced Settings, Network Settings, IPv4 Address Distribution, or DHCP Server.
• Find the Connected Device List: Locate the list of connected devices, which should include your mesh router.
• Reserve the IP Address: Find your mesh router's entry (identified by its MAC Address from Step 1) and select an option like "Reserve IP Address" or "Add DHCP Reservation."
  • Action: This tells your FiOS router to always give this mesh router the same internal IPv4 address (e.g., 192.168.1.2) every time it connects. This is functionally the same as a static IP for your purposes.
• Save Changes.

Step 3: Enable the DMZ and Point it to the Static IP The DMZ rule tells the FiOS router to send all unsolicited incoming traffic directly to your designated device.

• Navigate to DMZ Settings: On your FiOS router's web interface, look for a section labeled Firewall, Port Forwarding, or directly DMZ Host.
• Enable DMZ: Check the box or select the option to Enable DMZ.
• Enter the Reserved IP: In the field asking for the DMZ Host IP Address or IP Address of DMZ Device, enter the exact reserved IPv4 address you set in Step 2 (e.g., 192.168.1.2).
• Apply/Save Changes.

Your mesh router is now successfully placed in the FiOS router's DMZ, using a stable IPv4 address. All IPv4 traffic from the internet that isn't specifically for a known service (like TV) will be forwarded to your mesh router, allowing your mesh router to manage all of your home network's security and port forwarding.