$ORIGIN 30.172.in-addr.arpa. $TTL 86400 @ 1D IN SOA ns1.wLeiden.NET. hostmaster.wLeiden.NET. ( 2002081001 ; serial (d. adams) 3H ; refresh 15M ; retry 1W ; expiry 1D ) ; minimum $INCLUDE wleiden/ns-172 @ 0.0 PTR network.wLeiden.NET.