i am running Nextcloud on a Yunohost server on “domain.tld”. And I am running on the same server a collabora server under “office.domain.tld”.
The subdomain connects via a CNAME entry that points to the main domain.
The server is located at home and connects via DYNdns.
This setup is running fine for one day. As my FritzBox get’s a new public IP in the middle of the night Nextcloud isn’t accepting the Collabora server anymore. But the subdomain is still working in the browser. Only Nextcloud doesn’t accept it anymore.
If I refresh the SSL zertificat of the subdomain in Yunohost, it will run until the next IP change. But this is not a solution.
this sounds little weird for me as certificate’s in general have nothing to do with IP’s but only with hostnames… From your description I would guess your “Nextcloud instance” caches the IP of your “Collabora instance” so it fails to connect with it once the IP changes.
AFAIK Nextcloud doesn’t access Collabora at all - in general it is the client`s duty to reach out to Collabora instance and provide right URI to get access to files served by Nextcloud. You can check if the client has access to your Collabora instance when you visit Collabora check URI: "https://<your collabora domain>/hosting/discovery"