GeezerVison

>>> payload = f'0x{"0"*246}7f000001.example.com'
>>> payload
'0x0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000007f000001.example.com'

>>> import uvloop, asyncio
>>> async def loop_getaddrinfo(addr, port): return await asyncio.get_running_loop().getaddrinfo(addr, port)
>>> uvloop.run(loop_getaddrinfo(payload, 80))
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/mfulmer/miniconda3/envs/lm2/lib/python3.9/site-packages/uvloop/__init__.py", line 82, in run
    return loop.run_until_complete(wrapper())
  File "uvloop/loop.pyx", line 1517, in uvloop.loop.Loop.run_until_complete
  File "/home/mfulmer/miniconda3/envs/lm2/lib/python3.9/site-packages/uvloop/__init__.py", line 61, in wrapper
    return await main
  File "<stdin>", line 1, in loop_get_addrinfo
  File "uvloop/loop.pyx", line 1528, in getaddrinfo
  File "uvloop/loop.pyx", line 905, in uvloop.loop.Loop._getaddrinfo
UnicodeError: encoding with 'idna' codec failed (UnicodeError: label too long)

>>> import socket
>>> socket.getaddrinfo(payload, "80")
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/mfulmer/miniconda3/envs/lm2/lib/python3.9/socket.py", line 954, in getaddrinfo
    for res in _socket.getaddrinfo(host, port, family, type, proto, flags):
UnicodeError: encoding with 'idna' codec failed (UnicodeError: label too long)

>>> payload = f'0x{"0"*246}7f000001.example.com'.encode()
>>> payload
b'0x0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000007f000001.example.com'
>>> uvloop.run(loop_getaddrinfo(payload, 80))
[(<AddressFamily.AF_INET: 2>, <SocketKind.SOCK_STREAM: 1>, 6, '', ('127.0.0.1', 80)), (<AddressFamily.AF_INET: 2>, <SocketKind.SOCK_DGRAM: 2>, 17, '', ('127.0.0.1', 80)), (<AddressFamily.AF_INET: 2>, <SocketKind.SOCK_RAW: 3>, 0, '', ('127.0.0.1', 80))]

>>> socket.getaddrinfo(payload, "80")
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/mfulmer/miniconda3/envs/lm2/lib/python3.9/socket.py", line 954, in getaddrinfo
    for res in _socket.getaddrinfo(host, port, family, type, proto, flags):
socket.gaierror: [Errno -2] Name or service not known

>>> socket.getaddrinfo("0x7f000001", "80")
[(<AddressFamily.AF_INET: 2>, <SocketKind.SOCK_STREAM: 1>, 6, '', ('127.0.0.1', 80)), (<AddressFamily.AF_INET: 2>, <SocketKind.SOCK_DGRAM: 2>, 17, '', ('127.0.0.1', 80)), (<AddressFamily.AF_INET: 2>, <SocketKind.SOCK_RAW: 3>, 0, '', ('127.0.0.1', 80))]