zone "site1.example.com" {
  type master;
  file "/etc/bind/config/internal/db.site1.example.com";
};
zone "dhcp.site1.example.com" {
  type master;
  file "/etc/bind/config/internal/db.dhcp.site1.example.com";
};
zone "100.15.10.in-addr.arpa" {
  type master;
  file "/etc/bind/config/internal/db.100.15.10.in-addr.arpa";
};