What Is Bridge Mode and How to Enable It

Bridge mode turns off your router's NAT and DHCP, passing the internet connection directly to another device. It is the key to fixing double-NAT problems that break port forwarding and affect gaming, VoIP, and VPN performance.

What Bridge Mode Actually Does

When a router operates normally, it performs NAT (Network Address Translation) - it assigns local IP addresses to your devices and routes traffic between your home network and the internet. Bridge mode disables NAT and DHCP on the device, turning it into a transparent pass-through. All routing decisions are then handled by a different router downstream.

The primary use case is eliminating double-NAT. Double-NAT occurs when you have two devices performing NAT in sequence - typically an ISP-provided gateway and your own router connected to it. Both devices assign local IP addresses, which causes:

Port forwarding rules not working because traffic hits the ISP gateway first
Gaming consoles showing "Strict NAT" or "Moderate NAT" instead of Open NAT
VoIP call quality problems due to NAT hairpinning issues
VPN split-tunneling complications
UPnP not functioning as expected

You likely have double-NAT if your router's WAN IP address starts with 192.168, 10.x, or 172.16-31. These are private IP ranges - if your WAN IP is private, your ISP gateway is performing NAT before your router.

Bridge Mode vs DMZ vs IP Passthrough

Method	What It Does	Best For	Risks
Bridge Mode	Completely disables NAT and DHCP on ISP device, passes public IP to your router	Clean single-NAT setup with your own router	ISP gateway Wi-Fi disabled, all routing via your router
DMZ	Forwards all uninitiated traffic to a specific local device	Gaming consoles, servers when bridge mode not available	Target device has no ISP-level firewall protection
IP Passthrough	AT&T/Comcast term for DMZ - passes public IP to a specific device MAC	Same as DMZ, common on AT&T and Comcast equipment	Same as DMZ

Bridge mode is the cleanest solution when available. DMZ and IP Passthrough are preferable when bridge mode would disable ISP gateway features you rely on (like fiber ONT signal management on AT&T GPON equipment).

How to Enable Bridge Mode by Device

Comcast / Xfinity XB6, XB7, XB8

1

Log in to the ISP gateway

Open the ISP gateway admin panel (usually 192.168.0.1 or 192.168.1.1) and log in with admin credentials.
2

Find bridge mode or passthrough settings

Look in WAN settings, Advanced, or Firewall sections. The label varies: bridge mode, IP passthrough, transparent bridge, or DMZ.
3

Enable bridge mode and note the IP

Enable bridge mode targeting your router MAC address. The ISP gateway will stop doing NAT and pass your public IP to your router.
4

Reconnect your router to the gateway

Connect your router WAN port to a LAN port on the ISP gateway. Your router should receive a public IP directly.

AT&T BGW210, NVG589 (IP Passthrough)

1

Open http://192.168.1.254 and log in with the Device Access

Open http://192.168.1.254 and log in with the Device Access Code on the gateway label.
2

Navigate to Firewall > IP Passthrough.

Navigate to Firewall > IP Passthrough.
3

Set Allocation Mode to Passthrough and select your router's

Set Allocation Mode to Passthrough and select your router's MAC address from the Passthrough Fixed Smac list (connect your router first so it appears).
4

Save. The AT&T gateway passes the public IP to your router's

Save. The AT&T gateway passes the public IP to your router's WAN interface.

Generic ISP Router (True Bridge Mode)

1

Log in to the ISP gateway admin panel.

Log in to the ISP gateway admin panel.
2

Look for WAN Settings, Advanced, or Connection Type.

Look for WAN Settings, Advanced, or Connection Type.
3

Change the connection type from "Router" to "Bridge" or "Mod

Change the connection type from "Router" to "Bridge" or "Modem Only."
4

Save and reboot. Connect your own router to the gateway via

Save and reboot. Connect your own router to the gateway via Ethernet. Your router now receives the public IP.

Verifying Bridge Mode Is Working

After enabling bridge mode, log into your router admin panel and check the WAN IP address on the Status or Overview page. The WAN IP should now be a public IP address (not starting with 192.168, 10., or 172.16-31). If it shows a public IP, double-NAT is eliminated and port forwarding should work correctly.

Test port forwarding with canyouseeme.org to confirm external access reaches your local devices.

FAQ

Does enabling bridge mode affect my internet speed?

No - bridge mode does not affect bandwidth. It only changes which device handles routing and NAT. Your internet speed depends on your ISP plan and line quality, neither of which are affected by NAT routing at the local level.

I enabled bridge mode on my ISP gateway but now cannot access its admin panel

In bridge mode, the ISP gateway typically stops responding to its normal local IP (192.168.1.254, 10.0.0.1, etc.). To access it again, you usually need to connect directly to the gateway with an Ethernet cable and use a specific management IP. For Xfinity gateways in bridge mode, 192.168.100.1 usually works for the diagnostic page. Check your ISP's support documentation for the management IP when in bridge mode.