Hi,
My external ip has changed, what changes should I make to restart my server?
At the moment I have just redirected my domain to my new ip at my provider (OVH), but it still doesn’t work. I must have forgotten something else… Lets’s encrypt maybe ?
Anyway, how do I proceed in this case?
Thanks
I think you use a DNS name e.g. cloud.server.tld .
Have you changed the DNS settings e.g. CNAME?
Search in your DNS settings for your domain an change the settings for your nextcloud name.
Thank you for your answer.
I think it’s good : I change the value “to a server (ipv4 - A)” for my new external ip.
It seemed to me that it was the only thing to do. C’est en tout cas la seule configuration que j’avais faite initialement.
I think than it is all ok.
I think normal admins set mostly
A server.tld -> a.b.c.d
CNAME cloud.server.tld -> server.tld
But you must not change your settings.
Thanks to DeepL Translate: The world's most accurate translator . 
Oups, I forgot to translate this one 
and yes, thanks to deepl.
Do you have any idea what’s wrong?
Do the changes at my provider require a delay to be active?
Yes there is a delay in the internet on changing DNS entrys.
Sometimes hours.
You can test the DNS settings e.g. at the other end of the internet:
https://dnschecker.org
Also you can test it at home (your internet provider and your router).
Windows (Commandline):
nslookup cloud.server.tld
Linux:
host cloud.server.tld
dig cloud.server.tld
Perhaps you also can access through a mobile device from another internet provider.
This command still returns my old ip. Apparently, I just have to wait ???
You can ask alternative nameserver e.g. Google (8.8.8.8):
dig cloud.server.tld @8.8.8.8
Same answer, still the old ip…
You can also ask the nameserver of your nameserver provider. 
You don’t say what error you are getting, so it is difficult to know. If you are trying to access your server by its IP address you may need to update the ‘trusted domains’ section in your Nextcloud config.php.