Nest needs to be connected to the Internet in order for you to access and control it from your Nest Account. There are some routers that’ll incorrectly disconnect Nest from the Internet after 30 minutes or less of inactivity. Unfortunately, these routers don’t conform to the TCP/IP specifications around Network Address Translation (NAT) timeouts and are disconnecting Nest too soon.
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Nest uses Wi-Fi "Power Save Mode" to allow it to sleep and charge its battery while remaining connected to the internet. Not all Wi-Fi routers support this feature or implement it correctly.
When they don't, Nest will have difficulty sleeping and will restart in an attempt to reset its network connection. This may happen repeatedly if your Wi-Fi router is incompatible with the “Power Save Mode” feature.
Posted: Thu Jan 02, 2014 23:52 Post subject: My Nest Thermostat and DDWRT are WORKING GREAT
This are the settings I changed to accommodate the Nest Thermostat
UDP Timeout 3600s
Beacon Interval 221ms
DTIM 3
I am running V24 Sp2 build 21061
Cisco WRT400N - AR7161
Running DHCP on an Open network with MAC filtering only.
Nest 2nd Generation
Note: UDP timeout is found in Administration->Management. But Beacon Interval and DTIM are often NOT found in your Advanced Wireless settings. They are SSID-specific parameters, and the variable names will vary based on which radio you connect the nest to.
Mine were wl0_bcn and wl0_dtim but yours will vary.
Here is a friendly example for you. Forgive little errors, please.
Telnet 192.168.1.1
Name root
Password *******
nvram show
(This displays a long list of nvram vars. Dig in and find your beacon and dtim var names! You will find one set for each SSID you have.)
Replace my XX’s with your proper chars.
nvram set wXX_bcn="221"
nvram set wXX_dtim="3"
nvram commit
Best of luck. The Nest is a great thermostat. Sorry their own support has been so untechnical. A few magic numbers go a long way!
Thanks for the info, it helped. However, I think you meant to set the beacon interval to 211 ms, not 221 ms. It's better to set it as a prime number to minimize the risk of collisions among clients. Also, I haven't seen why the UDP timeout matters, I've only seen TCP connections from the Nest.
Based on my experience with my router (WRT54G) default values, the Nest connects every hour for about 5 mins, so it's offline most of the time. With the updated values, it's offline for about 15 mins at a time. Not perfect but much more usable. I'll keep testing.
Keep us posted.
I am new to Beacon and DTIM but as I understand it the router will save the client power by saving up communications. It should be communicating to Nest once every 211ms x 3 = 633ms.
I popped in those numbers because they were posted on this forum. ( I will double check that value, thanks. )
Nest didn't say they are TCP only, so I felt it proper to set UDP to be the same.
I would have guessed Nest would want DTIM much higher since a one or two second lag when accessing via the app would not be a problem.
However, my battery level is fine, and I am never offline for more than a second.
It works great.
I am so happy I ordered a second one.
Cheers!
Posted: Wed Jan 08, 2014 19:17 Post subject: Problem solved
Well, I was doing some tests with the beacon and DTIM values without much improvement when suddenly, my nest appeared online at all times. It turns out it had updated itself to the latest 4.0.1 version (from 3.5.x) and that seemed to have done it. The Nest people must have fixed the problem or found a workaround on their side.
What were your symptoms for this issue? I first noticed it when I saw it dropping off the network every minute or so when scanning with SoftPerfect Network Scanner.
I've been running my Nest & DD-WRT router without issue. I honestly didn't even think of the Nest when I made the switch to DD-WRT. I'm running a Netgear R7800.
I have a 2nd gen Nest and have not had any issues with dd-wrt. I also ran a 1st gen Nest and had no issues with dd-wrt. Have had a Nest and dd-wrt with several different routers for the past 5 years and no issues.
