Reverse DNS

There is a small script that updates the reverse record for a given ip address.

It can be called on the VPN VM as

snippet.bash

  /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).

Example:

snippet.bash

/home/jim/scripts/dns/./dyn-reverse-dns.sh 80.67.181.163 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. [1]
• 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).