Device with valid IP missing from device list

[bradleyw]

I've got a Nest Protect attached to my network that has a valid IP and is online but I cannot find it in the device list of either my primary or satellite. Any ideas?

[CrimpOn · Accepted solution]

I've given the Nest issue more thought.  Can't "prove anything" because my Orbi no longer logs things (NTP, DHCP assignments, etc.), but that's a different thread.

I know that my Nest connects to the Nest Cloud when it boots up because the Nest is controlled by a smart phone or tablet app that connects through the cloud.  Until a person opens the app, why would the Nest send any packets at all?  I don't see any reason for it to.  What that means (to me) is that the Orbi might see a DHCP request from the Nest, respond and put it into the "attached devices" table.  As time go by without hearing from the Nest, eventually the Orbi says, "guess that device isn't active anymore" and drops it out of the table.

As a test, I opened the Orbi attached devices page and, sure enough, no Nest.  Then, I opened the Nest app on my phone.  It's 72 degrees in my house.  Boom.. Nest pops up on my attached devices page almost instantly.  Just for fun, I left the Nest app open on my phone and watched the Orbi.  In less than 2 minutes, the Nest disappeared.  Do something on the app, and it appears.  Wait two minutes, and it disappears.  Don't even have to close the app.

When I've done Wireshark captures of my home network, I've always been surprised at how "chatty" most devices are.  They are sending packets all the time.  Looks like the Nest only talks when it has to.

Someone at Netgear probably knows exactly how long Orbi waits before forgetting a device, but they  also probably don't look at community forums and would be prohibited from telling users anything.

[FURRYe38]

Nothing matching the MAC address of the device on the connected clients list on the Orbi router? 

How many other devices do you have attached besides this particular device? 

Try this. Power off ALL other devices including this device. Reboot the Orbi router and let it come to ready. Power ON this device. 

Look at the routers web page with a PC and web browser to see if the device is listed.

[bradleyw]

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@FURRYe38 wrote:

Nothing matching the MAC address of the device on the connected clients list on the Orbi router? 

Correct. I looked for the MAC and the IP of the device which I checked from that device's own app UI. I verified that i was able to connect to the device.

How many other devices do you have attached besides this particular device? 

14

Try this. Power off ALL other devices including this device. Reboot the Orbi router and let it come to ready. Power ON this device. 

Look at the routers web page with a PC and web browser to see if the device is listed.

I tried this. It seemed to work temporarily but after a while the device disappeared. As far as I can tell the device still has a connection.

[CrimpOn]

My Nest thermostat behaves the same way.  It is definitely "on line": (1) the Nest front panel says it is and shows the correct IP, (2) I can use the Nest app on my phone or tablet to look at and change the temperature.  It has an IP assigned on the Orbi.  But it does NOT appear on the list of attached devices.

My guess is that once the Nest gets an IP and makes connection with the Nest "cloud", it never talks to the Orbi again.  i.e. doesn't try to open a new connection, make a DNS request, etc.  (I guess wrong a LOT.)  Ethernet switches know when a device is "turned on", because there is electrical voltage on the wire.  They do NOT know if a device is "connected" until it is powered up.  i.e. the wire may be "connected" but until there is a signal on the wire, it's not "connected".  There could be something buried in WiFi protocols that devices are supposed to maintain some kind of "heartbeat", but the WiFi AP might still talk to them even if they don't follow the protocol perfectly.

I have noted Orbi behavior like this before, and put it down to not having any idea what causes the Orbi to decide that a device is "attached."  I know what I (personally) mean by "attached", but I have never seen an explanation of what Orbi thinks it means.

[DenisF]

I have three nest protects on my network, 2 are wired and appear on the Orbi device list, the third is battery powered and does not appear.

I assume that in order to save battery power the battery nest protect only connects when it needs to.

[bradleyw]

@CrimpOn wrote:

My Nest thermostat behaves the same way.  It is definitely "on line": (1) the Nest front panel says it is and shows the correct IP, (2) I can use the Nest app on my phone or tablet to look at and change the temperature.  It has an IP assigned on the Orbi.  But it does NOT appear on the list of attached devices.

Thanks same here though mine is a Nest Protect and interesting my Nest thermostat seems to always show up in the device list for what it's worth.

My guess is that once the Nest gets an IP and makes connection with the Nest "cloud", it never talks to the Orbi again.  i.e. doesn't try to open a new connection, make a DNS request, etc.  (I guess wrong a LOT.)  Ethernet switches know when a device is "turned on", because there is electrical voltage on the wire.  They do NOT know if a device is "connected" until it is powered up.  i.e. the wire may be "connected" but until there is a signal on the wire, it's not "connected".  There could be something buried in WiFi protocols that devices are supposed to maintain some kind of "heartbeat", but the WiFi AP might still talk to them even if they don't follow the protocol perfectly.

That explanation makes sense to me.

@DenisF wrote:

I have three nest protects on my network, 2 are wired and appear on the Orbi device list, the third is battery powered and does not appear.

I assume that in order to save battery power the battery nest protect only connects when it needs to.

Thanks! Good insight. This Nest Protect is battery powered also. As I noted above, my wired Thermostat doesn't exhibit the same behavior.

[CrimpOn · Accepted solution]

I've given the Nest issue more thought.  Can't "prove anything" because my Orbi no longer logs things (NTP, DHCP assignments, etc.), but that's a different thread.

I know that my Nest connects to the Nest Cloud when it boots up because the Nest is controlled by a smart phone or tablet app that connects through the cloud.  Until a person opens the app, why would the Nest send any packets at all?  I don't see any reason for it to.  What that means (to me) is that the Orbi might see a DHCP request from the Nest, respond and put it into the "attached devices" table.  As time go by without hearing from the Nest, eventually the Orbi says, "guess that device isn't active anymore" and drops it out of the table.

As a test, I opened the Orbi attached devices page and, sure enough, no Nest.  Then, I opened the Nest app on my phone.  It's 72 degrees in my house.  Boom.. Nest pops up on my attached devices page almost instantly.  Just for fun, I left the Nest app open on my phone and watched the Orbi.  In less than 2 minutes, the Nest disappeared.  Do something on the app, and it appears.  Wait two minutes, and it disappears.  Don't even have to close the app.

When I've done Wireshark captures of my home network, I've always been surprised at how "chatty" most devices are.  They are sending packets all the time.  Looks like the Nest only talks when it has to.

Someone at Netgear probably knows exactly how long Orbi waits before forgetting a device, but they  also probably don't look at community forums and would be prohibited from telling users anything.

[bradleyw]

Thanks. That makes a lot of sense. In my case my Nest Thermostat always appears to be in the device list. The Protect seems to go away after a while which would make sense if it’s not actively exchanging data with the router regularly. Only challenge there is that I Don’t know how to activate the Protect the same way you do with the Thermostat. I supposed I could run a diagnostic test or something.