Interface option InterfaceChoice.Default not working for IPv6 #1562
Description
When trying to use InterfaceChoice.Default with IPv6 on Linux Python Zeroconf isn't able to start browsing/sending frames:
E.g. running this snipped:
import asyncio
import logging
from zeroconf import (
DNSQuestionType,
InterfaceChoice,
IPVersion,
ServiceStateChange,
Zeroconf,
)
from zeroconf.asyncio import AsyncServiceBrowser, AsyncZeroconf
logging.basicConfig(format='%(asctime)s %(message)s', level=logging.INFO)
logging.getLogger("zeroconf").setLevel(logging.DEBUG)
def service_browser_handler(zeroconf: Zeroconf, service_type: str, name: str, state_change: ServiceStateChange) -> None:
logging.info("mDNS service state change: %s - %s - %s", name, service_type, state_change)
async def browse_service():
_aiozc = AsyncZeroconf(interfaces=InterfaceChoice.Default, ip_version=IPVersion.V6Only)
_aiobrowser = AsyncServiceBrowser(
_aiozc.zeroconf,
["_matter._tcp.local."],
handlers=[service_browser_handler],
question_type=DNSQuestionType.QM,
)
await asyncio.sleep(5)
asyncio.run(browse_service())The same is true when trying to use dual-stack with IPVersion.All. Also the question type doesn't matter DNSQuestionType.QU won't get delivered either.
Leads to the following output:
2025-04-10 16:17:46,736 Creating new socket with port 5353, ip_version IPVersion.V6Only, apple_p2p False and bind_addr ('',)
2025-04-10 16:17:46,736 Created socket <socket.socket fd=8, family=10, type=2, proto=0, laddr=('::', 5353, 0, 0)>
2025-04-10 16:17:46,736 Adding (('', 0, 0), 0) (socket 8) to multicast group
2025-04-10 16:17:46,736 Listen socket <socket.socket fd=8, family=10, type=2, proto=0, laddr=('::', 5353, 0, 0)>, respond sockets [<socket.socket fd=8, family=10, type=2, proto=0, laddr=('::', 5353, 0, 0)>]
2025-04-10 16:17:46,781 offsets = questions=0, answers=0, authorities=0, additionals=0
2025-04-10 16:17:46,782 lengths = questions=1, answers=0, authorities=0, additionals=0
2025-04-10 16:17:46,782 now offsets = questions=1, answers=0, authorities=0, additionals=0
2025-04-10 16:17:46,782 Sending to (ff02::fb, 5353) via [socket 8 (('::', 5353, 0, 0))] (36 bytes #1) <DNSOutgoing:multicast=True, flags=0, questions=[ptr[question,QM,in,_matter._tcp.local.]], answers=[], authorities=[], additionals=[]> as b'\x00\x00\x00\x00\x00\x01\x00\x00\x00\x00\x00\x00\x07_matter\x04_tcp\x05local\x00\x00\x0c\x00\x01'...
2025-04-10 16:17:46,782 Error with socket 8 (('::', 5353, 0, 0))): [Errno 99] Cannot assign requested address
Traceback (most recent call last):
File "/usr/lib/python3.13/asyncio/selector_events.py", line 1268, in sendto
self._sock.sendto(data, addr)
~~~~~~~~~~~~~~~~~^^^^^^^^^^^^
OSError: [Errno 99] Cannot assign requested address