Solved Cannot connect anymore to some domains (googleapis.com, bitbucket.org, ?)

[Sygmoral]

Since a few hours ago, our server can not longer connect to some domains. It started with clients contacting us because pdfs could no longer be generated, because it was using webfonts. Okay, easy fix, we downloaded the webfonts and are hosting them ourselves now for pdf generation.

But soon after I noticed that I also can no longer "git pull" or "get fetch origin", with my repository being on Bitbucket. It simply can't connect.

I tried the very basics, with for example "wget https://fonts.googleapis.com/css?family=Roboto:400,700". I see that it uses the ipv6 to connect, which is fine, but it stalls for about a minute, and then finally downloads the file.

I tried "wget https://bitbucket.org/...", it also connects to a ipv6, but it times out after a few minutes, then tries again on another ipv6 address, then times out again.

I tried "wget https://flxion.com/wp-content/uploads/2020/08/Flxion-Logo.png" which is just a file hosted on some other webserver, it also connects via ipv6, but this time it is downloaded in an instant.

So "some" servers - in this case googleapis.com and bitbucket.org - have started refusing or delaying connections from my DirectAdmin server. I would prefer not to restart the whole server to avoid downtime. What can I try to figure this out? Something I can restart?

A few notes: Centos 7; I have disabled named; I have CSF running (which I'm a newbie at, and it's over a year since I made any changes there).

 

[Sygmoral]

Okay, after several minutes, the bitbucket call actually went through, but only after trying 3 ipv6 addresses, and finally when it then tried an ipv4 one, it worked.

Remember that my little png file download was successful, so at least some ipv6 connections work.

1. Can I make my server prefer ipv4 addresses when it tries connecting to a domain?
2. How might I debug the fact that it cannot connect to some ipv6 addresses?

 

[Sygmoral]

It's night here now, so I rebooted the server anyway... and that seems to have solved the issue. Could be interesting to know a solution if this ever happens again, though.

[update] Our VPS provider just sent a message about the ipv6 issues yesterday, so that caused it. I guess I can stop worrying about this, although a way to 'prefer ipv4 before ipv6' could still be interesting.

 

[Richard G]

I wouldn't know to fix your issue, so I did not reply (probably like others here), but I do appreciate that you post your experience and the solution.
It might indeed be interesting for some cases if there is a way to prefer ipv4 above ipv6 if present, but I'm afraid there is no such option.
However.... keep up the good work!