[Pdns-users] Dynamic DNS questions

[Thomas Mieslinger]

 > [..]
 > Trying to set up 4.0.3 dynamic registration and although I can see
 > server registering I am not clear on how the registration, update and
 > scavenging works.

reading rfc2136 will give you insight.

 > I do not see a timestamp added to change_date field on records table,
 > and whenever a second registration attempt comes in I do not see
 > anything changing.
 >
 > Looking at dynamic registration for a reverse lookup zone, if a new
 > server picked up a previously registered IP it registers it again and
 > two entries are in the reverse lookup zone.

How about using dnscap to capture all dns packets on the server? Then 
you can analyze when which packet arrived.

Alternatively you could turn on the general log in the mysql database se 
see all queries executed to full the ddns requests.

 > I was looking for documentation on dynamic registration but I could
 > not find any.

To me the pdns4 rfc2136 documentation has no shortcomings. Enjoy it here:
https://doc.powerdns.com/md/authoritative/dnsupdate/

Cheers

Thomas