How to isolate a device in a topic related to its clientid?

[aboxsystem]

We need to isolate the device under its own topic i.e: {clientid}/branch/leaf so the device has access only to its own deviceid topic tree?

[anon79473925]

Hello,

You have several ways for doing this. In the following link you have several ideas for that:

Sending messages to specific MQTT devices

Hi there I have multiple devices that I’m setting up and managing through the API I want to target specific messages to each device, and only that device should have access to that message. No device should be able to publish. It seems MQTT doesn’t let you target like this, so I’m looking at doing it another way. Option A. Filter all devices so they can’t publish (looks like it can be done) Filter all devices so they can’t subscribe to any channels (looks like it can be done) Now I need to…

In essense, you can use Filters [1] to make ensure some devices are the ones that can publish or subscribe. This way you create these device isolated topic tree:

[1] Sending messages to specific MQTT devices

The idea is to create a set of filters like this:

• Filter for deviceA (or set of devices like A)
• Filter for deviceB (or set of devices like B)
• …
• …
• Filter for admin devices (bypass all restrictions)
• Deny all filter

This way if a device has no match to any filter, will reach last filter (deny all).

Best Regards,

[aboxsystem]

It is possible i.e mosquitto to have a filter with wildcard “clientid” (%c) so you create a topic: “%c/#” so it applies to each device that connects. There are wildcards in myqtthub?

[anon79473925]

Hello,

We have just published an engine update that allows to configure topic filters using %c and %u replacements,
just like mosquitto, to provide matching to connecting clientId and userName value.

Here you have additional indication:

Managing MQTT filters with MyQttHub to control what can be published

1. Introduction to MyQtthub filters With MyQttHub filters you can easily: Control what can be PUBLISHed creating policies for allow-then-deny or deny-something-rest-allowed. Use filtering to activate Stashing function to store matched messages into durable MyQttHub storage backend. We are going to see how filters are configured by example. See next. 2. Creating an allow-then-deny MQTT filter with MyQtthub In this case you want: To create a filter that allows only certain topics. Optional…

Best Regards,