Hi, I posted this on the linux forum, but since it is probably more related to ISPconfig, I am posting it here... I have debian 9, ISPconfig3.1, with latest version of bind. I have a static IPv4, a domain, that my DNS server is authoritative for. I am able to create forward zones without any problem, but when I try to create reverse zone, it only creates a file with .err extension. Doesn't matter if I create signed zone or not. There are no related error messages in /var/log/syslog ... Name of the zone is like 444.333.222.111.in-addr.arpa. , since I don't have the whole subnet. Only one IP. The file, that ISPconfig creates looks like this: Code: name of the file: pri.444.333.222.111.in-addr.arpa.err content: $TTL 3600 @ IN SOA ns1.domain.eu. info.domain.eu. ( 2017081501 ; serial, todays date + todays serial # 3600 ; refresh, seconds 540 ; retry, seconds 604800 ; expire, seconds 3600 ) ; minimum, seconds ; 444.333.222.111.in-addr.arpa. 3600 PTR ns1.domain.eu just one thing is suspicious - if I try to query the PTR record using nslookup, I get message, in the syslog The .err extension is present immediatelly, no matter if there is or isn't any record. Could someone please help me to debug this?