How do I configure AT&T BGW210 in bridge mode?

I recently had my service installed from AT&T, and I also have the Arris BGW210 modem. I was successful in setting up IP passthrough with my Asus RT-AC3100 router. I basically connected the router to port 1 of my modem(from the router's "internet" port). Then in the modem, go to Firewall->IP Passthrough, and set the following:

"Allocation Mode": Passthrough

"Passthrough Mode": DHCPS-fixed

"Passthrough Fixed MAC Address": I selected my router from the list, but you could manually enter the MAC address.

After this, ensure your router is set to automatically get assigned an IP from the modem, in my case, under "WAN", I set "WAN Connection Type" to Automatic IP. After this you'll want to turn off WiFi on the modem, and I also disabled all Firewall features since my router handles that(do that at your own risk). Lastly, make sure to reboot the modem first, then your router. Hope this helps!

I am trying to do the same thing. I previously had my gateway (from different company) 192.x.x.x. The BGW210 is also configured as 192.x.x.x.   My router is 10.0.0.1.  It all worked fine with the old gateway.  When I try to do the pass through with the AT&T gateway, my router doesn't show. I think it is because it is not on that subnet (192x).  Is it possible to keep my configuration?  I have another router (for another part of the house) too and it is all configured so I really don't want to change everything.  

Good afternoon @michaeljc70!

I understand you are having some problems with the passthrough on your BGW210 gateway. I regret to hear you are having issues with trying to get this done, but I would be happy to help you find a resolution.I have a few options which would help!

As long as the Class A private subnet does not have to route through the U-verse gateway, it will work. So you can keep the 10.x.x.x network behind your router, but it has to have a 192.x.x.x or 172.x.x.x IP for it's WAN IP, and you'll have to login to your U-verse gateway to update the DHCP pool settings to work with that. You can also click here for a walkthrough. I hope this information helps.

Let us know if you need further assistance.

Lucas, AT&T Community Specialist

This is great information, and I've followed all the instructions, and set up IP Passthrough to my Netgear router. However, I am still getting a double NAT issue on anything connecting through my Netgear router. If I do a tracert... I get say 10.0.0.1 (private ip) and then 192.168.1.254 (from the gateway), then off into the internet from there. If I've done IP Passthrough, why am I still getting the double NAT? How can I fix?

dsgreen48 Did you ever get this figured out?

What wan/internet IP is your EA9500 being assigned?  If it's a public IP, I believe that pass through is working.  If it's a 192.xx or 172.xx then something isn't right.

i think you would need to RESET all devices.  Once your Gateway is up and  running you still need To PUSH THE RESET BUTTON on your personal Home Network machines for EXAMPLE your APPLE TIME CAPSULE.

WIRED OR UNWIRED i still get 988.00 Download & 987.00 Uploads.  I reset all of my Apple Time Capsule which is my main Base Station in my Studio.  Then in another Office i have AIR PORT EXTREME & in the LIVING ROOM i have the AIRPORT EXPRESS.   A lady at APPLE helped me configure my Apple Time Capsule.  And what ever she did when we did it worked better with FIBER OPTIC than XFINITY.  I only had to push the RED RESET button and have not had a problem since i have gotten AT&T FIBER OPTIC 1000Mbps or 1Gbps installed.  My internet is lightening fast i have never experienced speeds like this constantly i am really blown away. I hope the price comes down once people get it it's too expensive $80 a month is  just STUPID to pay for INTERENET

Thanks for posting this solution. Worked great with my new Moto BGW210 and eero mesh router. The eero lists its WAN as the WAN that the BGW210 has passed to it, and no double NAT'ing as far as I can tell. Working well, including IPv6 and the rest. Haven't turned off the firewall on the BGW210 yet, but that seems like a good idea since the eero has one and not great to have too many layers slowing things down.

Very happy to have run across this very useful note!

Just had service installed today.  Everything is working great with the BGW210, and now I'm about to attempt this passthrough setup so I don't have to reconfigure my network.  Quick question before I proceed:  Once done, how will I access the BGW210's configuration page?  Will it still be accessible at the same default IP (192.168.1.254) from a computer connected to my own Linksys router?

Yes, after you put the BGW-210 in IP Passthrough mode, you will still access the its settings at its default IP address (192.168.1.254). Just as you did before you put it in IP Passthrough mode.

Just one caution, when setting up IP Passthrough mode, be careful to get the IP Passthrough mode pointed at the right device (your Linksys router). If you give the wrong router MAC address or pick the wrong device out of the device list that the BGW-210 presents, you'll have two routers running on your network. This was a little difficult for me, since I have an eero mesh system, with three identical nodes. Plus each node has several MAC addresses. The first time around, I got the wrong MAC address for the gateway eero node, and I thought that I was in IP Passthrough mode at that point, but wasn't. Turned out that I had double NAT'ing going on, which meant that I had two routers going. This configuration worked, but I wanted the eero to be the only router, and that wasn't the case until I got the IP Passthrough mode set correctly.

You can look on the internet and see how to check for double NAT'ing if you want, to verify that you've got everything set up correctly. That's actually very helpful.