+$TTL 1h
+@ IN SOA ns root (
+ 2017052001 ; Serial
+ 4h ; slave refresh
+ 15m ; slave retry time in case of a problem
+ 4w ; slave expiration time
+ 1h ; maximum caching time in case of failed lookups (1 hour)
+ )
+ IN NS ns1.dehnerts.com.
+; IN NS ns2.dehnerts.com.
+ IN NS ns3.dehnerts.com.
+ IN NS ns1.sipb.org.
+ IN A 18.102.208.15