Wemo across two devices

I have recently purchased a few Wemo smart plugs to help identify some of my always on load. My problem is that I also have two Sense meters (two panels, no easy way to use one meter). Both Sense meters detect all of the plugs becuase I have a single wifi network in the house which is causing some issues. I have not found a way in the app to exclude Wemo plugs that are detected. Am I missing something?

There is no native way to exclude certain smart plugs at this time. The same goes for all connected devices. One possibility would be to have each Sense monitor on a separate IP subnet, and then have the smart devices you want on panel 1 to be on that panel’s subnet and the smart devices you want on panel 2 to be on that panel’s subnet.

Separating that would require a substantial rework of my home network. I would have to create separate SSIDs for each panel and move everything around. The duplication of SSIDs on the same frequency would cause noise on the channel and potentially reduce the overall speed of the wifi in my house. I’m not overly thrilled by that idea. Is there any way you can list this as a feature request for the future? I would think a “disable” checkbox would not be an overly hard thing to add to the system compared to some of the larger requests.

Looking from the outside, your suggestion is one of numerous pieces needed to make multi-panel fully work. Not really that smart to add just that one feature in a piecemeal way.

1 Like

You’re welcome to submit it as a feature request in the Product Wishlist subforum. Just note that smart plugs are already not a featured used by the majority of our userbase. 400A support and smart plugs would cover an even smaller amount of users. We don’t purport to be compatible with 400A homes at this time, and while we plan to support them in the future, piecemeal features likely aren’t the solution for that.

As a point to clarify, do the devices just need to be on a separate subnet or do they need to be on a completely isolated broadcast domain (e.g. VLAN) from each other? My router apparently can have two different subnets running on the same SSID. The only catch is that they share the same broadcast domain at that point.

This isn’t something we’ve thoroughly tested as it’s not a normal use, but the same SSID will likely not work. The broadcast domains should be isolated. Feel free to try the same SSID/separate subnet though. Let us know what happens.

I don’t want to derail the thread, so feel free to PM back, but what kind of router do you have? I’m curious as to how/why it would allow you to create two subnets on the same SSID and how it further knows which subnet to put traffic on. I also wonder - because its a router, not a switch, depending on what their implementation is, its possible that it isn’t the same broadcast domain because it is doing things behind the scenes and just making it look easy.

So I’ve had a good bit of luck getting this working now that I’ve looked at it and broken some of it apart. First, to answer the question of which router, it’s a Cisco 800 series so I have a few more options to do things that many home routers cant. It’s an all-in-one router/switch/wifi with the full Cisco IOS feature set.

The first thing I did was capture and check out the traffic being sent between the Sense and the Wemo boxes. Wemo uses mDNS for discovery which was an immediate cause for concern about the broadcast domains. The positive though is that it still was a point-to-point connection for actual telemetry data. The theory, which played out mostly successful, was that if I could block the point-to-point across panels then I would at most only see the plugs not in the panel as items with a 0W draw. I configured my router/switch/wifi to have 2 different (small) subnets on the same broadcast domain (for the network guys, these were secondary addresses on the existing vlan interface). I then configured my DHCP server to hand out static assignments to the Sense and Wemo devices which would put them in those subnets. I also configured an access list to prevent the two new subnets from talking to each other with the hope that it would block telemetry data from passing across.

After a bit of tinkering and some reboots of the Wemos everything went into their proper subnet and could talk to the world (but not each other across panels). The Sense that I had not enabled Wemo discovery on immediately began to work when I enabled discovery. It found all of the plugs in the house, but it was only able to get data from the ones that were in the local subnet (as expected). So worst case now on that panel is that I have some extra devices hanging around which aren’t impacting my statistics. The Sense that did have discovery on before was a bit more complicated. It would not connect to any of the Wemos including the ones that it had previously worked with. I attempted to enable/disable discovery only to find the devices not show up at all. The final thing that fixed this was to power cycle the Sense itself. This almost immediately fixed the issue. The only oddity is that the Wemo on the other panel is not showing up on this one (not actually a complaint, just odd that it didn’t add it to the mix). My concern here is that discovery works by mDNS so the Sense should have picked this up immediately. I’m worried that they can not handle an IP change of the Wemo which is a very real possibility on a home network. Also, as soon as I disabled discovery my android app would crash when I attempted to open Always On. That went away as soon as I power cycled the Sense so I’m assuming it just had a bunch of stale data that needed to be purged.

So long story short, I achieved my goal of having this split apart. Again, this seems over complicated compared to a switch in the app to just simply ignore a plug, but it’s done.

The only other gotcha that I will be careful of is the addition of new plugs. Provisioning of the Wemo is a little flaky out of the box. I believe that I will need to create the static DHCP assignment before bringing it online to ensure it gets put in the right place the first time.

1 Like