recent Nest Wifi Pro problem: can't obtain IP address

[eeeee]

In the last week, I've noticed a couple of problems.  The more serious one is one particular device not being able to connect -- first it was a Nest camera, and then after fixing that, my Pixel 7 repeatedly reported (even after reboot) "can't obtain IP address" and would not connect.  Power-cycling the main point (plugged into an Xfinity router) didn't change the situation, but doing a "restart" of the network in the Home App did -- though with the camera, I had to restart the Xfinity router as part of the recovery, too (and do this twice before things started working).

The less serious issues is intermittent drop-outs -- a Chromebook getting Wifi from a point (not the main one) loses Wifi connectivity enough that it switches to another network (the one direct from the Xfinity router).  This can happen multiple times a day.  I've also had a Nest Speaker (on the same point) similarly flake out and lose connectivity (and not be able to get back on until the Nest Wifi was restarted).  Connectivity to this point is "great" so it shouldn't be an issue with getting to the point.

Any advice?

[eeeee]

The problem happened again just now.  All of a sudden, my Chromebook dropped off of the Nest Wifi network and would not reconnect -- a DHCP issue per the pop-up on the Chromebook.  Restarting the Nest Wifi (via the Home app) got it so the Chromebook would connect again.  I have a very vanilla setup -- nothing has been changed from default settings.  This is getting pretty frustrating.

[LovelyM]

Hi eeeee,

Please perform a 2-minute power cycle on your entire network to re-establish the connection on your connected devices. Here's how: 

1. Disconnect the power from the modem.
2. Disconnect the Ethernet cable and power cord from the parent point.
3. Disconnect the power cord from the child points.
4. Leave everything unplugged for 2 minutes.
5. Connect the power cord to the modem then to your router and points.

If the issue persists, you can try factory resetting your Wifi devices and see if that helps. 

Cheers,
Lovely

[eeeee]

I've never tried turning EVERYTHING off at the same time like that -- just did it.  I'll let you know what happens...

[eeeee]

Well, that didn't totally fix the current issue -- my Chromebook just changed to "wifi available via phone" for a few seconds, before getting back on the local point.  This is somewhat of an improvement as the chromebook got on the same point (and didn't switch to a different one or to a different network -- the neighbors).  I'll wait a while longer and see how often this happens and what it reconnects to.

[LovelyM]

Hey eeeee,

I'll take note of your update. I'll keep this thread open and let me know your observations so I'll be able to take a closer look into this.

Sincerely, 
Lovely

[eeeee]

There was at least one other network drop-off -- this one lasted longer (over five seconds), but no further DHCP-like problems now that the Xfinity router doesn't have any WiFi clients.  I had also (before yesterday) turned off "auto-connect" for the Xfinity WiFi, which may be why my Chromebook doesn't connect to it during one of these drop-offs (but it's not connecting to the neighbor's WiFi, either, and it used to do that sometimes).  The other thing that's changed is that previously (before turning off everything and then restarting as you suggested), the Chromebook would connect to some other point (seen by lower signal strength) rather than the one 4 ft. away -- I haven't seen that happen again -- it seems to reconnect to the same nearby point.  This isn't the worst problem, but it is a pain when you lose connectivity randomly for a few seconds (luckily only a couple times a day yesterday).

[Dan_A]

Hello there eeeee,

We’re chiming in to see if you’re still having the same behavior with your Wi-Fi connection as before or not anymore. Are they in Bridge mode or back on Double NAT? 

For more information, check out this helpful guide about bridging and its uses: Bridge mode.

Keep us posted.

Kind regards,

Dan

[olavrb · Accepted solution]

Sounds like you are using the Xfinity router as a router and Wi-Fi point too? This is not needed nor recommended, as it can cause strange problems and performance degradation. Ideally you'd set the ISP equipment in bridge mode, sometimes known as bypass mode. Read more about it here:

• https://dongknows.com/double-nat-vs-single-nat/
• https://support.google.com/googlenest/answer/6277579?hl=en

I found this from Xfinity on bridge mode:

• https://www.xfinity.com/support/articles/wireless-gateway-enable-disable-bridge-mode

[eeeee]

Thanks very much -- you've got the situation sussed out.  I just got off a long call with Nest Support and they suggested either bridge mode or setting up a DMZ -- I'd strongly prefer the latter as I like having the WiFi network on the Xfinity modem as a back-up (and one or two devices use it directly).  The DMZ stuff seems about as straight-forward to set up, but needs the IP address of the ethernet-attached WiFi point -- do you know if that's the WAN IP in the Home App advanced settings vs. the LAN IP?

[olavrb]

I'd just go with bridge mode tbh. Keep it simple, avoid problems.

I haven't experienced much with DMZ. Does Xfinity bind one of its' ports to it, with a local IP to go with it? Then the main Nest Wifi should detect that IP with DHCP.

Here is what Xfinitt says about DMZ:

• https://www.xfinity.com/support/articles/configure-dmz-wifi

[eeeee]

Thanks for the further reply.  I agree that bridge mode would be a lot simpler, but then I lose the Xfinity WiFi -- I'll have to think about whether I really want to do that.  (And yes -- I don't know how the Xfinity modem handles ports and addressing -- more research needed if I go down the DMZ path.)

The other weird thing is that these problems just started a couple weeks ago -- and I've had the same setup for years (ever since the first Google WiFi came out).  Things have worked fine with the Nest WiFi Pro since it came out until just recently....

[olavrb]

There is no recent firmware update to regular Nest Wifi, that I know of at least. But that's the thing with double NAT and Nest Wifi, it might work well, it might not. It seems to have more problems with double NAT than many other home routers.

[LovelyM]

Hi eeeee,

I want to ensure you are good to go. Please reply to this thread if you still need assistance so I can give you a helping hand.

Cheers,
Lovely

[LovelyM]

Hello everyone,

Your assistance here is greatly appreciated, @olavrb.

@eeeee, thanks for reaching out. It looks like your questions were already addressed. I want to make sure that everything is covered on your end. Feel free to reply to this thread if you have additional questions or concerns.

Best,
Lovely

[eeeee]

Thanks for asking!  I've gotten rid of the double-NAT issues (I think) by just removing all devices from the Xfinity modem WiFi -- with no one asking for anything, there's no conflicts and I'm no longer getting DHCP problems where devices fall off and are then unable to connect at all.  But there's still one problem -- at least one WiFi point seems to periodically go off-line (just for a few seconds), but long enough that a Chromebook only 4 ft. away tries to connect to some other point (or other network, like my neighbor's).  I can tell when this happens because either (a) the WiFi signal strength drops, or (b) I get a pop-up about connecting to my phone for internet connectivity.  This happens a couple of times a day that I've noticed.  I don't know if this is related to issues with having the Xfinity modem not configured as a bridge, but don't quite see how that would cause just one point to glitch.  (I've never seen a glitch on devices that are likely connected to the primary point.)  Right now, I'm just living with the annoyance...