Solaris 2.5.1 uses BIND version 4.9.3 and with patch 103663-XX are required to fix some native security holes within BIND. Noticibly, the DNS daemon in solaris 2.5.1 may spins when attempt to lookup a mock up DNS entry within your lab environment. Maybe you'd want to check if your DNS is working correctly by issuing nslookup and truss the in.named process. --Joe