ATT Fixed Wireless Gateway Bypass

ATT Fixed Wireless Internet service consists of an Outdoor Antenna with a built-in modem and an ATT Residential Gateway. A Power-over-Ethernet injector is used to power the Antenna/Modem.

A handful of ATT Fiber customers figured out how to bypass the residential gateway. Since the same gateways are used for Fixed Wireless Internet, I wonder if it was possible to do the same.

After some packet captures and testing, I determined the following:

  1. Nearly all traffic was tagged for vlan 4001 or vlan 4002
  2. The MAC Address of the Linux router needs to the same as the Residential Gateway (or the modem won’t respond)
  3. DHCP on VLAN 4001 gave a 192.168.11.x address
  4. DHCP on VLAN 4002 gave an “Internet” address of 10.x.x.x address (Carrier Grade NAT)

Note: For ATT Fiber, 802.1x Authentication is required between the residential gateway and the modem (ONT). 802.1x Authentication is not used for Fixed Wireless Internet. Be aware of this, if reading other guides.

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