Internal DNS proposal

wikimedia.org

 i.wikimedia.org
   ...zwinger.i.wikimedia.org 10.0.0.4
   ...albert.i.wikimedia.org  10.0.0.3
   svc.i.wikimedia.org
     ...ns.svc.i.wikimedia.org        10.0.1.1
     ...db-master.svc.i.wikimedia.org 10.0.1.2
     ...mail.svc.i.wikimedia.org      10.0.1.3

DNS for i.wikimedia.org is slaved between 3-4 machines using a service IP, 10.0.1.X. failover can be done via e.g.

shouldn't be noticably less reliable than /etc/hosts, and much easier to manage. network 10.0.1.X can be allocate for service IPs.