Hi,
I’ve had the following issue on Manjaro; I’d like to know what piece of software is most likely to be the culprit and therefore to which bugtracker I should report it. And also, in the event that I face the same issue again in the future, I’d like to know if there’s a workaround that doesn’t require reboot (e.g. restart some service or flush some caches).
Here it goes:
Summary
On a server that I manage, which already had a working website with domain example.com (obviously that’s not the actual domain), I configured a subdomain newsubdomain.example.com (that’s not the real subdomain name either) within the same domain. Meaning that I added the A and AA DNS records and created a separate virtual host. This subdomain happened to be hosted on a different server, but I’m pretty sure that’s irrelevant.
After I set everything up, I checked the following:
- the new subdomain records had propagated to the entire world according to https://www.whatsmydns.net/
- I checked at Google Public DNS that the new subdomain was visible by Google’s DNS
- the web servers for both the original domain (which had already been working before) and the new subdomain were both working (which is also confirmed by the following two points)
- I asked a coworker to access http://newsubdomain.example.com from their computer from my same country and it was accessible
- I checked from a third unrelated host (in another country) that I could
wget http://newsubdomain.example.com
So, on my Manjaro local computer, I tried opening http://newsubdomain.example.coom in Google Chrome, and it failed with ERR_NAME_NOT_RESOLVED; so I also tried to ping the subdomain from a terminal and it also failed.
I changed my network configuration to use Google’s DNSs 8.8.8.8, disconnected and reconnected to the network; retried and it kept failing.
So I rebooted, and sure enough, it could access the domain.
It’s very likely (I’m almost sure) that I had also tried and (expectedly) failed to access the subdomain before I set it up. So maybe the failure response from some DNS had been cached somehow. I certainly had (successfully) accessed the root domain before.
Steps to reproduce
see Summary
Should be something like this:
- try to ping a subdomain that isn’t reachable, whose root domain is reachable
- also ping the root domain which will succeed
- try opening both in a browser (should succeed with the root domain and fail with the subdomain)
- set up the server so that the subdomain is now reachable
- make sure the DNS information has propagated, i.e. that the subdomain is indeed reachable from any other existing machine
- make sure your local network is set up to use a DNS server that does know about the subdomain
- disconnect and reconnect physically to the local network
- try again to reach the subdomain via ping and a browser (make sure to restart the browser before)
Actual result
- the subdomain is still unreachable until reboot
Expected result
- the subdomain should be reachable without needing a reboot.
Note: I create new domains all the time almost on a daily basis, and don’t remember having this issue. MAYBE this is specific to the situation where a subdomain becomes reachable, which belongs to a root domain that was already previously reachable. But I’m just speculating based on the fact that this is a use case that I don’t hit nearly as often.