Reverse DNS

You can set the reverse DNS (PTR) name of a server's primary IPs and of floating IPs. Mail servers in particular need a PTR record that matches their host name.

1. Create the forward record first: the host name must resolve (A or AAAA) to the IP address. Otherwise the change is refused with 400 invalid_input.
2. Set the PTR record:

odx server set-rdns --hostname mail.example.com web-1                      # the server's primary IPv4
odx server set-rdns --hostname mail.example.com --ip 2001:db8::1 web-1     # its IPv6 address
odx floating-ip set-rdns --hostname www.example.com ip-1
odx server set-rdns --reset web-1                                           # remove the entry

With the API, POST /primary_ips/{id}/actions/change_dns_ptr or POST /floating_ips/{id}/actions/change_dns_ptr with {"dns_ptr": "mail.example.com"}. Send {"dns_ptr": null} to remove the entry.

• The name must be a fully qualified host name such as mail.example.com.
• The change is made right away; the returned action has already succeeded.
• You can change reverse DNS at most 60 times per hour per project.
• When an address is released (its server or floating IP is deleted), its reverse DNS entry is removed.
• If reverse DNS cannot be managed for an address at the moment, the request fails with 503 resource_unavailable.