I have a self-hosted Discourse server (in my own network, on my own server).
In a new post I am pasting a URL to a site which is hosted in the same local network as my Discourse server, i.e. both Discourse server and the target site reside behind the same NAT.
I am getting the following error:
When pasting the very same URL anywhere else (Facebook, Twitter etc) β the preview is generated just fine.
.
My suspicion is Discourse back-end server (docker? Linux?) is not able to resolve the DNS name correctly, even though the host name can be resolved in my local network just fine:
Where should I check/troubleshoot on why the name is not being resolved by Discourse?