Getting home assistant to commuicate using Tailscale

Installation
,
1

Collecting sensor data from remote site.

I have two water pumping stations that I want to be able to monitor various information, e.g. amount of water int the tanks, water flow out of the pumpstations, pump status. The first station (Pumphouse 1) is physically close so that is hard wired to my own WiFI and I can connect it to my local lan. The second station (Pumphouse 2)is some distance away (+/- 1 km) and there is no possibility of a wired connection. That pump house has been equipped with a Teltonika router using 4g mobile data to connect with the internet.

Pumphouse 1 has the following equipment:

Teltonika router lan 192.168.15.0/24
Pi 3 hosting Tailscale
Pi 4 hosting my instance of Home Assistance, The Tailscale app is also installed on HA
Shelly Uni Plus equipped with a Denver temperature sensor. This is just temporary and only to help with proof of concept.

Pumphouse 2 has the following equipment

Teltonika router lan 192.168.10.0/24

Pi Zero hosting Tailscale
Shelly Uni Plus equipped with a Denver temperature sensor. This is just temporary and only to help with proof of concept.
HA is working 100% at Pumphouse 1 and can read the sensor information coming from the Shelly sensor at the same location.

If I connect locally to the Pumphouse 2 lan I can read the sensor data from the Shelly there.

Tailscale is working fine. I can see all three units on the Tailscale administration page

And now, finally, my main issue. I have not been able to access sensor data from Pumphouse 2 and include it in HA at Pumphouse 1.

I would really be grateful for any input as to how to enable HA to accept the remote data. HA at Pumphouse 1 cannot see the sensor at Pumphouse 2. And of course if my strategy is wrong and there is a better way to achieve my goal I would be open to any suggestions.

2

How is the data from the second sensor arriving at your HomeAssistant server? Via a routed direct network session? MQTT packets? How is it transversiing your two VLANs? How have you configured it to do so? Can your second router be configured as a bridge to the first?

3

You have pinpointed the problem exactly. At the moment HA at Pumphouse 1 cannot see any data from Pumphouse 2. My understanding was that HA, Pumphouse 1 and Pumphouse 2 are all included in Tailscale that HA would be able to read the data from Pumphouse 2, but it cannot. I really need advice on the best practice of allowing this to happen.

4

A little more explanation. Thanks to Tailscale all the units are connected.

Using my iMac on a separate lan and also connected to Tailscale I can connect to the Shelly sensors at both the Pumphouse locations and also HA at Pumphouse 1. So its not an interconnectivity problem, its a question of how to get HA at Pumphouse 1 to read sensor at Pumphouse 2