绑定地址选择本地目的地，可达性还取决于完整路径

import json,subprocess,uuid
image="python@sha256:528257d48c1da0dcecc2e725d1ae34498d60c965f1241e39cd6a85a8859bdf84"
program=r"""
from contextlib import ExitStack
import errno,json,socket

def read_exact(stream,length):
    result=b''
    while len(result)<length:
        part=stream.recv(length-len(result));assert part,'unexpected end of stream'
        result+=part
    return result
def listener(stack,address,family=socket.AF_INET,v6only=None):
    stream=stack.enter_context(socket.socket(family,socket.SOCK_STREAM))
    if v6only is not None: stream.setsockopt(socket.IPPROTO_IPV6,socket.IPV6_V6ONLY,v6only)
    stream.settimeout(1);stream.bind((address,0));stream.listen(4)
    return stream
def exchange(server,address):
    with socket.create_connection((address,server.getsockname()[1]),timeout=1) as client:
        connection,peer=server.accept()
        with connection:
            connection.settimeout(1);client.sendall(b'ping');assert read_exact(connection,4)==b'ping'
            connection.sendall(b'pong');assert read_exact(client,4)==b'pong'
            return {'listener':server.getsockname(),'accepted_local':connection.getsockname(),'peer':peer}
def refused(server,address):
    try:
        with socket.create_connection((address,server.getsockname()[1]),timeout=1):pass
    except ConnectionRefusedError:return 'ECONNREFUSED'
    raise AssertionError('unexpectedly connected')
with ExitStack() as stack:
    narrow=listener(stack,'127.0.0.1')
    one=exchange(narrow,'127.0.0.1');other=refused(narrow,'127.0.0.2')
    duplicate=stack.enter_context(socket.socket())
    try:duplicate.bind(narrow.getsockname());raise AssertionError('duplicate bind succeeded')
    except OSError as error:assert error.errno==errno.EADDRINUSE
    unassigned=stack.enter_context(socket.socket())
    try:unassigned.bind(('192.0.2.99',0));raise AssertionError('unassigned bind succeeded')
    except OSError as error:assert error.errno==errno.EADDRNOTAVAIL
    wildcard=listener(stack,'0.0.0.0')
    both=[exchange(wildcard,a) for a in ['127.0.0.1','127.0.0.2']]
    narrow.close();wildcard.close()
    only6=listener(stack,'::',socket.AF_INET6,1)
    six=exchange(only6,'::1');four_rejected=refused(only6,'127.0.0.1')
    dual=listener(stack,'::',socket.AF_INET6,0)
    mapped=exchange(dual,'127.0.0.1');assert mapped['peer'][0].startswith('::ffff:')
    print(json.dumps({'narrow':one,'other_loopback':other,'duplicate':'EADDRINUSE','unassigned':'EADDRNOTAVAIL',
        'wildcard':both,'ipv6_only':six,'ipv6_only_v4':four_rejected,'dual_stack':mapped}))
"""
name='xbcatm-socket-'+uuid.uuid4().hex[:10]
try:
    result=subprocess.run(['docker','run','--rm','-i','--name',name,'--network','none',
        '--memory','128m','--pids-limit','64',image,'python3','-'],input=program,
        capture_output=True,text=True,timeout=60)
    assert result.returncode==0,result.stderr
    print(json.dumps(json.loads(result.stdout),ensure_ascii=False,sort_keys=True))
finally:
    subprocess.run(['docker','rm','-f',name],capture_output=True,text=True,timeout=10)