On my Windows 10 desktop machine, I am running the following bit of Python (3.10.9) to make an HTTP POST request:

import json
import requests

response = requests.post(
    url="https://foo.bar/baz",
    headers={
        'Content-Type': "application/json",
        'Authorization': "bazz",
    },
    data=json.dumps({"key":"value"})
)

When I ran the code in PyCharm, I found that the call to the post() method consistently stalls for about 63 seconds before returning. As this is an unreasonably long time to get a response from this API, I ran the same code in the same way on a different computer and found that the call returns almost immediately with a good response.

Having profiled the code in PyCharm, I can see that it’s the call to Python socket.connect() method that causes the 63-seconds delay.

Following advice I’ve found online, I’ve disabled IPv6 on the Ethernet adapter that I use to access the internet:

Once I’ve done that, when I run the code, it returns immediately with no delay.

My question is – Why is this happening and how can I re-enable IPv6 on the Ethernet adapter and not experience the 63 second delay?

Additional observations:

• The https://foo.bar API application seems to have both IPv6 addressed and IPv4 addresses:

❯❯ nslookup foo.bar

Server:  vulcan.local
Address:  192.168.1.1

Non-authoritative answer:
Name:    foo.bar
Addresses:  2606:4700:20::****:****
          2606:4700:20::****:****
          2606:4700:20::****:****
          172.67.***.***
          104.26.***.***
          104.26.***.***

• When enabled, the IPv6 feature is configured to have default values (as far as I can tell).