Anyone using the ARRIS BGW210 with ATT and the new ALIEN System?


  • Hello! I just upgraded from the AmplifiHD system to the Alien + Mesh Extender. I have everything working fine at this point - except the bridged mode issue. If you enable bridge mode on the Alien then it turns off a bunch of features -specifically the parental control that allows me to create profiles and schedules for my kids.

    I'm curious if anyone has any experience putting the BGW210-700 into bridged mode. I've found a couple writeups on it - seems fairly straightforward...but I've also read that even with the router in bridged mode it's still essentially doing a double NAT. Before I go donking around just curious if anyone has done this and is seeing the right speed/throughput as expected.

    I did notice pretty significant speed increases from WIFI6 connected devices when I initially switched the Alien into bridged mode vs the out of the box double NAT configuration. I'm hoping for the same result with the BGW210-700 configured in bridged mode, but I guess I'll just have to test it out and see.

    I'm have ATT GigaPower - so 1GB/up and down and I do get those speeds from the ATT router test and as well as the speed test on the Alien even when it's doing double NAT.

    My main issue is everything not being on the same network subnet. Chromecast is a perfect example. If my TV is hardwired to the BGW210 and getting a 192.168.1.X address and my Note20 Ultra is connected to the Alien and getting a 192.168.115.X address - it just won't work. Some stuff seems to work, like PLEX...but it's hit or miss depending on the app and it's ability to negotiate the double NAT setup.

    Appreciate any help or insight in advance. If/when I get around to changing my setup I'll post my results as hopefully someone else can find it useful at some point.


  • @Ken-Lince I would reach out to ATT, they have some equipment that can be put in to bridge mode and some equipment they won't allow to use bridge mode on. I would recommend you place the ATT device in bridge mode and wire/connect everything to the Alien router so they are on the same LAN network.


  • @Ken-Lince I've done it and it works perfectly. Also, there's no double NAT if done correctly. Lastly, if you're bridging (IP Passthrough) the AT&T modem, you cannot have anything hardwired to it because it's not handing out IP addresses. The only device that should be connected to the modem should be the Alien. If you need more ethernet ports you should get a simple switch.

    Go here to see how this is done:

    https://community.amplifi.com/post/18685


  • @bshaheen Thanks for sharing the resolution!


  • IP Passthrough on AT&T is not the same as bridge mode. The best proof for this is you can still access your gateway through the web interface at 192.168.1.254. If it were true bridge, you wouldn't be able to, as you'd be "hopping" over the gateway. Check your trace route.
    A second proof for this is if you go to your gateway you will see your NAT table is still very active. It's very misleading because it might look like your Alien is getting a public IP address. That's just a DHCP trick. This is still double NAT, make no mistake about it. The only way to get around it is with an EAP proxy or the dumb switch method.

    Plenty of discussions on this on DSLreports as well.


  • That feels like the right thing to do. Unfortunately, ATT's tech support is pretty horrible. I'm not even going to waste my time with that. Unless you hit the lottery and happen to get someone who can do more than flip through the canned scripts they provide to their first level folks - it's pretty futile.

    When I get a break I'll flip the ATT router into bridged mode and see how that goes.


  • @dani82 And if you are unlucky enough to have a Pace 5268AC, even in DMZ+ mode, life is not good. You'll lose the ability to synchronize time across your LAN because you will lose access to port 123 when you go into DMZ+ mode. So, it doesn't really bridge, AND AT&T denies access to time sources. it took me quite a bit of homework to discover this was the root cause of my domain controller not receiving time updates.

    I am told the Arris BGW210-700 does pass time by a friend who has one, but getting one from AT&T is impossible. I contacted tech support and twice ordered a BGW210-700, and got two Pace 5286ACs instead. Sent them both back. On the good side, a wired client is showing over 900 Mb down via the Pace and Amplifi Alien using Ookla's tool. I am hoping this stays like this for some time to come.


  • @lobuxracer Let us know if you are able to use the Arris.


  • @UI-AmpliFi As luck would have it, the neighbor down the street had an issue and AT&T sent a tech out to fix it. I saw the truck, then the tech and I asked him if he had an Arris BGW210-700 on the truck. He did indeed have one and now it is installed. I am in passthrough mode and seeing an external IP address bound to the Internet interface on the Amplifi router, and I have validated NTP is passing to my domain controller in this configuration. Just one problem. The Arris router shows near gigabit speeds on its internal speed test and a laptop plugged into one of the switch ports on the Arris gets near gig speed as well, but the Amplifi router is only getting ~95 Mb. It feels like the link speed negotiation isn't working correctly, and when I set the link speed on the Arris manually, it completely broke the link. Is there a way to validate link speed on my Amplifi router to be sure it's connecting at gigabit speed? There is nothing on the Arris to tell me what the negotiated link speed is.

    Follow up I found the page with the link speed. It is autonegotiating at 100Mb. Why would that be?


  • @lobuxracer Ah, never mind. Bad RJ45. Replaced it and now it's screaming. 950 down, 838 up on Speedtest.net. Followed bshasheen's instructions for configuring the Arris, and everything is as it should be. Checked NTP, and it's also working perfectly. Loving my network again!


  • @lobuxracer That's great to hear. Glad I could help.


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