How to add a PTR record
There is a small script that updates the reverse record for a given ip address.
It can be called on the VPN VM as
/home/jim/scripts/dns/./dyn-reverse-dns.sh <ipv4 ou ipv6> <nom de domaine à y assigner> <serveur DNS à updater>
For the moment, the DNS server is 172.16.42.2 (I just set up this argument for more modularity in the future).
/home/jim/scripts/dns/./dyn-reverse-dns.sh 188.8.131.52 brique.e-jim.be 172.16.42.2
It can have those different return codes:
- 0 - All went fine, thank you.
- 1 - First argument is not a valid IP (either v4 or v6)
- 2 - Second argument is not a valid domain name
- 3 - The third argument is not a valid DNS server name or IP
- 4 - The chosen domain name doesn't resolve into the given IP. 
- 5 - nsupdate (the tool used behind) returned an error.
- 33 - There are less or more than 3 arguments
Most of the time, more info can be found in the stdout.
I hope this can help someone implement reverse DNS into ISPng (including the needed verification that the user has administrative rights on the IP).