Hi, I have this problem. I have a multiserver installation ispconfig 3 with debian. (apache + mysql + postifix + dovecot + bind9) I have 3 name server ns1 ns2 and ns3. All work fine. ns2 and ns3 are replications of ns1. Now I need to change public IP of ns2. I change network ip, change hosts configuration on all machines, change dns configuration in ispconfig panel, and change ip on my registrant. Now when I change a dns record from ispconfig panel, ns1 anche ns3 are ok, ns2 log said: Feb 29 16:52:59 ispconfig-ns2 named: client xxx.xxx.xxx.xxx#31138: received notify for zone 'xxx.it': not authoritative (for all domain) Help me... please.