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Multi's profile

New Member

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3 Messages

Wed, Oct 5, 2022 7:36 PM

Help with turning off Bridge Mode - is impacting all my Nest WiFi devices

I have a fiber setup, and it works great on my wife's PC, which is connected to the AT&T modem with ethernet.  She gets the gigabit speeds, no problem.  BUT, I have been having serious issues with my Nest WiFi units, and when troubleshooting with Google support, they looked in some logs I shared, and said the following (which I need help with!):

"Based on the result of your status report, your modem is using a private IP address (192.168.1.254) as its routing capability is still enabled and it manages the internet bandwidth that your Google Wifi is using. It could be the reason why your internet isn't working.
Best to turn off its routing capability (bridge mode) to keep your devices from having a double NAT scenario or setup DMZ on the modem for your Google Wifi router — this will open all ports, allowing Cloud Services to communicate properly.
If you don't have access or you're not familiar with it, best to reach out to your ISP to change the settings on your modem/gateway."

Can someone provide guidance on how to do these suggested changes, to see if it helps?  Thanks!

JefferMC

ACE - Expert

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30.3K Messages

2 months ago

You probably do not want two routers, both doing NAT processing on your Internet connection.  When you install a Nest Router behind an AT&T Gateway, both in their default configurations, that is what you get.  There are two basic ways to avoid this:

1) Put the AT&T Gateway in IP Passthrough mode.  That causes it to pass the external IP and most traffic through to your router, removing the NAT on the Gateway.

2) Put the Nest in "Bridge" mode (which is technically putting it in Access Point mode).  This causes your Nest to not act as a router, but instead simply as an Wi-Fi Access Point.  All the routing and NAT will be performed by the AT&T Gateway.  Note that this will disable many features of the Nest (such as Parental Controls, time of day restrictions, etc.)

Both are viable configurations.  It's just a question of which one you want to do.

New Member

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3 Messages

2 months ago

Thank you @JefferMC for that info!

To help me arrive at my choice of #1 or #2, here are some thoughts/concerns:

I am leaning toward option 1, and putting the Gateway into IP Passthrough mode, but how will that affect a couple of things I have plugged into ports (beside the Nest), namely, my wife's PC, and a DVR for a camera system?  Will they continue to operate as they do now, without any special changes?

IF I went with option 2, and did Bridge mode on the Nest, would that affect the Ethernet out from the main Nest router, which plugs into our TV? 

Sorry if these are ignorantly simple Q's!

JefferMC

ACE - Expert

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30.3K Messages

2 months ago

Those are fine questions.  As it is you have separate networks, and if you go IP Passthrough, you'll still actually have separate networks (the Gateway will still operate as a NATting router, just not for your Nest traffic).  Your wife's PC and a DVR can still exist out there.  What they cannot do now, and will not be able to do in the future in IP Passthrough, is access resources connected to the Nest.  If that's not a problem now, then it shouldn't be then.

If you go #2, you'll actually bringing things connecting to the Nest into the network managed by the Gateway, which means the restrictions I mentioned (e.g. the PC not getting into the Nest's network) would go away.  The Smart TV connected by Ethernet connected through the Nest router should continue to function as it does now.  Currently the Nest is giving out IPs, in "bridge" mode, all of the requests from things connecting to the Nest, will be passed to the Gateway and it will give them an IP.  I mention this because if you had something like a printer that you connected to from other systems, you may need to "find" that printer again.

ATTHelp

Community Support

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204.2K Messages

2 months ago

Let's help you pick the right gateway mode for your internet, @Multi.

 

Thanks for your help @JefferMC.

 

The IP Passthrough mode will make your router act like a modem and pass all packets through to the personal router.

As far as your devices, you would need to set up any other custom settings on the personal router.

  • Only one device can be put into passthrough mode.
  • Placing a device in passthrough mode will remove firewall protection provided by the AT&T gateway.
  • When a device is configured in passthrough mode, it will be assigned a WAN IP instead of a LAN IP. Other devices connected to your gateway may no longer be able to share files with the device in passthrough mode.

In a bridged mode, the modem/gateway device does not authenticate, does not manage, has no ability to perform any firewall protection, and does not allow for remote access into the modem/gateway device. The subsequent device connected to the DSL/Broadband modem/gateway device has to perform all these tasks, if needed.

Bridged mode is not possible on the AT&T platform. 

 

Please reach back out, and let us know if this helps.

 

Latoya, AT&T Community Specialist

 

New Member

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2 Messages

1 month ago

Even though IP Passthrough seems to work, when performing a traceroute you can still see two internal hops, one to the Nest Wifi router and one to the ATT Gateway. Google support calls this, rightly so, a "double NAT" and blames all performance degradation on this double NAT. Is there any way to further simulate "bridge mode" to remove the double internal network hops?

tonydi

ACE - Guru

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8.6K Messages

1 month ago

No, not "rightly so".  Just because there's a hop does not mean it's doing double NAT.  In IP Passthrough mode the gateway isn't doing any NAT operations on the packets being sent to the Google Wifi. 

This performance thing has been a problem with the Google system for quite some time (do a Google search), even on non-AT&T systems.

New Member

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2 Messages

1 month ago

Thank you @tonydi. Agreed that it may not be a true double NAT, but the issue is that Google support won't escalate because they have fixated on the double NAT they can see from the traceroute being the issue. I have never heard of double NAT leading to a 95% reduction in upload speeds but guess that doesn't matter. Any suggestions for work arounds or you think it is just the Google software fowling everything up?

tonydi

ACE - Guru

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8.6K Messages

1 month ago

Yeah, I guess I shouldn't expect any better technical "support" from Google than, say, AT&T or Comcast.  That's just typical finger pointing designed to get you to go away.

Frankly, I'm not sure what's going on.  Like I said, if you Google 'google nest wifi slow' and even add "ip passthrough" to the search you'll see tons of people with the problem.  At one point on a Google forum they said they were aware and were waiting for firmware to fix it, which seems to indicate ownership of the issue.  The FW came and some people saw speed increases, but many did not.

New Member

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3 Messages

1 month ago

Glad to see this continued discussion, @Nwfipron as I'm experiencing exactly what you described, after setting up IP Passthrough on the AT&T gateway.

@MadeByGoogle on Twitter has been very responsive (in a DM with me), and suggested several things after the configuration was changed on the gateway.  At first, I thought things were better, but suddenly I was experiencing random pathetic speeds again.  They are trying to figure out next steps, but right now, I think they are stumped, which is what @tonydi was referring to!

If I need to switch to something else that performs reliably, I will do so.  I just want to have confidence that whatever I plunk down several hundred more dollars on, will actually work right with the gateway!  Open to suggestions for alternate hardware.

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