[async_upnp_client.ssdp] Received error: [Errno 101] Network unreachable

[There doesn’t seem to be a networking category or tag, so sticking it here.]

HA 2024.5.1 running in Docker on Debian.

My logs are spammed with this, every 30 seconds.

2024-05-28 20:49:23.051 ERROR (MainThread) [async_upnp_client.ssdp] Received error: [Errno 101] Network unreachable, transport: <_SelectorDatagramTransport fd=24 read=polling write=<idle, bufsize=0>>, socket: <asyncio.TransportSocket fd=24, family=10, type=2, proto=0, laddr=('::', 56238, 0, 0)>
2024-05-28 20:49:53.052 ERROR (MainThread) [async_upnp_client.ssdp] Received error: [Errno 101] Network unreachable, transport: <_SelectorDatagramTransport fd=24 read=polling write=<idle, bufsize=0>>, socket: <asyncio.TransportSocket fd=24, family=10, type=2, proto=0, laddr=('::', 56238, 0, 0)>
2024-05-28 20:50:23.053 ERROR (MainThread) [async_upnp_client.ssdp] Received error: [Errno 101] Network unreachable, transport: <_SelectorDatagramTransport fd=24 read=polling write=<idle, bufsize=0>>, socket: <asyncio.TransportSocket fd=24, family=10, type=2, proto=0, laddr=('::', 56238, 0, 0)>

There have been some issues on Github that were auto-closed without a fix.

A few discussions about it, eg

again, no real conclusion, just dies without answer.

I am not sure when it started. I really don’t look at the logs very often.
The only thing I can see in HA that isn’t working, is a Bluetooth adaptor [that I don’t use]. Many of the integrations I have use networking, and work fine.

If I understand correctly, some part of Home Assistant is trying to listen on :: [any IPv6 address]. In issue 69669, chishm inferred that " ('FF02::C', 1900, 0, 2)" meant interface #2. So from “(‘::’, 56238, 0, 0)” I would infer that it’s referring to interface 0, but interfaces are numbered from 1 on Linux! So what is it really doing?

I had to restart the container for an unrelated reason, and these events have stopped.