Hi, a few days ago I was having issues accessing HA using the hostname “homeassistant.local:8123” from a different network. I couldn’t figure out what was wrong, I changed the DNS a few times from Pi-hole to the gateway and rebooted everything, eventually things just started working, no idea why. Today I decided to take a deeper look using Wireshark and noticed something strange. Just some background:
- 192.168.1.xxx = Primary Network
- 192.168.100.xxx = Secondary Network
- 192.168.100.69 = HAOS
- Everything else = Random Devices
So the strange thing I found, and my theory as to why I couldn’t access HA by using the hostname, is that sometimes HA doesn’t respond to the mDNS query, especially when the query originates from the primary network.
When I access HA from the same/secondary network, the mDNS query was sent from the source device and HA sometimes responded to it, all makes sense, except when HA just didn’t respond. Why?
When I try accessing HA from the primary network, it seems like HA just doesn’t like to answer that mDNS query. I think that my gateway is set to repeat the mDNS query from the primary network to the secondary network and so that’s why query IP address source is set to 192.168.100.1 (I’m no network expert, I learned about mDNS a few days ago). And even though HA never responded, right now I am still able to access HA by name, I’m thinking it’s because my gateway has the IP address cached(?).
Anyway, the question, why doesn’t HA ever respond to queries from the gateway, 192.168.100.1, and why does it sometimes not respond at all?
I hope this all makes sense. I apologize if I use the wrong terminology, I’ll edit the post as I learn what is the correct word.