Interessting problem with the ICMP integration (ping)

DH5AT · May 2, 2025, 6:35pm

Hello,

i have a interesting configuration problem with the ICMP integration.

Ping to an IP-Adress (e.g. 8.8.8.8) works without problems.
Ping to an IP-Adress (eg. 192.168.88.51) works without problems.
Ping to a DNS Name (eg. www.spiegel.de) works without problems.
Ping to a local DNS Name (e.g. solaris.nahemuehle.local) don’t work.

But, if I ping the local DNS name from the console I get proper answer from the DNS Server.

I have no idea what could be causing this.

Axel

Edwin_D · May 2, 2025, 7:06pm

.local is mDNS, not DNS. Similar, but different.

The DNS server is not what answers, the resolved ip address does. Apparently ping con the console also resolves through mDNS, the ICMP integration does not.

Personally I have intermittent problems with esp mDNS and I’m not alone. It may be related to this:

github.com/home-assistant/home-assistant.io

mDNS/Zeroconf is not fully supported in HA Core via Docker

opened 11:37AM - 04 Aug 20 UTC

closed 01:38PM - 04 Aug 20 UTC

pedrolamas

## The problem The [current documentation](https://www.home-assistant.io/inte…grations/discovery/#mdns-and-upnp) states that one should use host network to have mDNS/Zeroconf discovery working in Docker, however I've came to realize that it works with just a few devices (like Chromecast) and most of them actually fail! With HA Core container is on the host network, the container will get the mDNS entries and Zeroconf integration will get notified of them and even start the flow to notify the admin that a new device that can be integrated has been found. However, the notification never actually appears as the container is unable to resolve the ".local" mDNS names, so the flow terminates! The reason for this is because the HA images are based in Alpine and unfortunately Alpine doesn't have the necessary support for mDNS names resolution (normally via libnss-mdns). This is also the reason why HA Supervised installations have an mDNS reflector and an internal DNS resolver (that basically allows for regular DNS queries to also resolve mDNS entries). So I believe that these two documents need to be changed to reflect this limitation: - https://www.home-assistant.io/integrations/discovery/#mdns-and-upnp - https://www.home-assistant.io/docs/installation/docker/ (top warning)

DH5AT · May 3, 2025, 7:19am

Thanks for the hint. I solved the problem.

francisp · May 3, 2025, 7:23am

Can you share your solution?

DH5AT · May 3, 2025, 10:36am

My solution was to change the domain name from nahemuehle.local to nahemuehle.tld.
In my installation I use a Mikrotik router with RouterOS. I changed in IP → DHCP Server → Networks the domain name. The devices which get a IP over DHCP are listed in the DNS Server as static member. This functionallity is provided over a dhcp-lease-script.