Do I have to give up on separate VLANS?

[tmjpugh]

@stevegroom

If HA Yellow is not able to connect to any network, is there a way to connect locally in order to recover?

HDMI cable, TV and direct connection

[francisp (Francis)]

Won’t work, the yellow does not have a HDMI port.

[stevegroom]

Making progress here.

So I built a test HA using an old RPi3 B+
Once it was minimally set up, I tried various ha network and ip commands and was able to make these changes without losing connectivity.

1. ensure the HA hardware is using DHCP with a dynamically assigned address - so if you confuse the config, it should always have a usable IP address that you can connect to.
2. Confirm the regular network config - on my Unifi switch, the HA instance was on the IoT vlan 20.
3. Configure the Unifi switch to support multiple VLANS

Port                    active
Native VLAN / Network   IoT (20)
Tagged VLAN Management  Custom
Tagged VLANS            Main (50)

Advanced                Auto

4. Install the SSH add on to HA.
5. Add vlan 50 to the HA ethernet port

ha network vlan enu1u1u1 50 --ipv4-method auto --ipv6-method auto

The following commands might be useful

ha network info | more
ip link
ip addr show
ip link delete dev enu1u1u1.50

I restarted the RPi and was able to reconnect to HA on 8123 and over ssh

The settings > system > network now shows the second network interface as a vlan

I’m now setting up Open Thread Border Router using a Sonoff Dongle Plus E, and once I confirm that works, I’ll repeat these steps on the HA Yellow.

[davidrapan (David Rapaň)]

Oh yeah I totally forgot about multiple ways of HA installation cause I’m always using HAOS through qemu. But I’m glad you found a way how to set it up! Taking notes.

[brendan]

What a lot forget to take into account is that Matter relies on ipv6 and mDNS, which i tricky across VLANS because mostly (for matter) it is using the link local address, which not routable, which means link local can’t route acrosss VLANs. Not to say it is impossible to get Matter to work across VLANs, but it it wasn;t designed to work across VLANs.
Multi homing your HA instance is likely the best work around, but there is not going to be a 100% guarantee Matter devices will work across different VLANs without consdierable faffing around.

I am no expert in Matter of course, but this thread has some good information Home Assistant can’t add Matter devices that are in a different VLAN - Configuration / Matter/Thread - Home Assistant Community (home-assistant.io)

[agners]

@brendan

What a lot forget to take into account is that Matter relies on ipv6 and mDNS, which i tricky across VLANS because mostly (for matter) it is using the link local address, which not routable, which means link local can’t route acrosss VLANs. Not to say it is impossible to get Matter to work across VLANs, but it it wasn;t designed to work across VLANs.
Multi homing your HA instance is likely the best work around, but there is not going to be a 100% guarantee Matter devices will work across different VLANs without consdierable faffing around.

This sums it up quite nicely. I’d only want to mention that the resolver integrated in Matter SDK should be able to handle multi homing. But the Home Assistant Matter Server currently scopes link-local addresses which are sent from the Home Assistant companion app. I’ve added a comment to the linked thread.