Best way to check if there is internet?

[Lars Liedtke]

P.S.: for ping a startingpoint can be icmplib, for dns dnspython and for 
http requests. But consider as well if you want to check for IPv4 and/or 
IPv6 Connectivity.

Am 07.02.22 um 13:47 schrieb Lars Liedtke:
> Each Browser is doing it differently and even Windows or 
> Linux-Desktopmanagers (NetworkManager).
>
> I have had cases, where one tool told me I had Internet and another 
> one I hadn't.
>
> So What Chris Angelico wrote is propably the best way, ping e.g. 
> Google, do a DNS lookup and try http for Status 200. Each with its own 
> Errorhandling and if you have got all three, then it is propable that 
> you have "Internet".
>
> Cheers
>
> Lars
>
> Am 07.02.22 um 10:33 schrieb Abdur-Rahmaan Janhangeer:
>> Popular browsers tell: No internet connection detected. A function that
>> goes in the same sense. Unless they too are pinging Google.com to 
>> check ...
>>
>> Kind Regards,
>>
>> Abdur-Rahmaan Janhangeer
>> about <https://compileralchemy.github.io/> | blog
>> <https://www.pythonkitchen.com>
>> github <https://github.com/Abdur-RahmaanJ>
>> Mauritius
>>
>>
>> On Mon, Feb 7, 2022 at 1:28 PM Chris Angelico <rosuav at gmail.com> wrote:
>>
>>> On Mon, 7 Feb 2022 at 20:18, Abdur-Rahmaan Janhangeer
>>> <arj.python at gmail.com> wrote:
>>>> Greetings,
>>>>
>>>> Using the standard library or 3rd party libraries, what's the
>>>> best way to check if there is internet? Checking if google.com
>>>> is reachable is good but I wonder if there is a more native,
>>>> protocol-oriented
>>>> way of knowing?
>>>>
>>> What do you mean by "if there is internet"? How low a level of
>>> connection do you want to test? You could ping an IP address that you
>>> know and can guarantee will respond. You could attempt a DNS lookup.
>>> You could try an HTTP request. Each one can fail in different ways,
>>> for different reasons. It's best to test what you actually care about.
>>>
>>>> Even this URL recommends checking if a domain is up as a way to 
>>>> check for
>>>> internet connectivity:
>>>>
>>> https://www.ibm.com/support/pages/checking-network-connectivity-when-using-python-and-ibm-resilient-circuits 
>>>
>>>
>>> That talks about a misconfigured proxy as being the most likely cause.
>>> Is that something you're trying to test for?
>>>
>>> There is no single concept of "there is internet". (Other than, in a
>>> trivial sense, that the internet does exist.) What you need to know is
>>> "can I use the internet?", and ultimately, that depends on what you
>>> need it to do.
>>>
>>> ChrisA
>>> -- 
>>> https://mail.python.org/mailman/listinfo/python-list
>>>
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