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How do we move devices on a separate Wi-Fi network with no internet access into Hermetry

How do we move devices on a separate Wi-Fi network with no internet access into Hermetry

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Translated from Türkçe by AI ·

Hello, a topic came up at the company where I am doing my internship (they build hotel automation). In hotels, the IT teams want to separate IoT devices from the guest and staff network and place them on a separate Wi-Fi network (separate SSID, separate VLAN) that never has internet access. The rooms have ESP8266-based temperature/humidity and door sensors, and they talk to each other over local MQTT.I have two questions. First, is there a standard for “Wi-Fi devices that are not connected to the internet”? Or does every company do it its own way? Second, we want to see the data from these devices in Hermetry, but the network has no internet egress. Does every device need its own permission opened, or is there another way? The IT team says “we don’t open firewall rules one device at a time”.

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Translated from Türkçe by AI ·

If you mean a standard, I don’t know of a single “offline IoT standard”. Everyone uses local MQTT, Modbus TCP or HTTP. But I’m sure the solution to your second question is a gateway.

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Translated from Türkçe by AI ·

We experienced exactly this in our hotel, a building with 140 rooms. I agree with Oğuz Bey: there is no separate standard, it is an architecture issue.What we did: the IoT VLAN was kept closed to the internet. We put a Raspberry Pi 4 with two legs on that VLAN. One leg is on the IoT network, where it listens to the local Mosquitto. The other leg is on the management network, and it is only allowed outbound TCP 8883. We had IT write a single rule: “from this IP to the Hermetry broker host, 8883 outbound”. No inbound port is open.The Pi is defined in Hermetry as a single device and marked “This device is a gateway”. It sends the room sensors’ data under its own name using v1/gw/* topics, and Hermetry creates each sensor as a child device itself on its first report. The room sensors need no identity in Hermetry.

PUBLISH v1/gw/connect
{"device": "oda-214-klima", "type": "oda-sensoru"}

PUBLISH v1/gw/telemetry
{"oda-214-klima": {"values": {"temperature": 22.4, "humidity": 51}},
 "oda-214-kapi":  {"values": {"door_open": 0}}}

If Hermetry has a profile with the same name as the type field, it uses that profile, so all room sensors’ alarm rules are in one profile. The default limit is 500 children per gateway, which is more than enough for us. Each child device is also counted separately, so choose your plan accordingly.If needed, you can also send commands and shared attributes to child devices. The Pi receives them via v1/gw/rpc and v1/gw/attributes and forwards them to the room device. We don’t send commands to the rooms, we only monitor them.Details: Devices behind a gateway

Modbus sadece register'dır, ta ki olmayana kadar.
Accepted solution♥ 5

Translated from Türkçe by AI ·

Now it’s very clear, thanks Gamze Hanım. I explained to the IT team “one IP, one outbound rule” and they accepted it right away. I tried it with a Pi in the test environment during my internship, and 6 test sensors came in as child. On the first attempt I forgot to mark the gateway, and after a few messages the session closed. Turning on “This device is a gateway” in the device settings fixed it.

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Translated from Türkçe by AI ·

That shutdown is classic: three rejected topics close the session within a minute. We had the same thing on the first day.

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