We have a Server 2008 primary domain controller. At times certain websites become inaccessible until we clear the cache on the DNS. any ideas on how to cure this symptom without having to add forwarders to our DNS? Below is the ip info for our dns server Server IPCONFIG: Windows IP Configuration Host Name . . . . . . . . . . . . : ptssrv01 Primary Dns Suffix . . . . . . . : PTS.local Node Type . . . . . . . . . . . . : Broadcast IP Routing Enabled. . . . . . . . : No WINS Proxy Enabled. . . . . . . . : No DNS Suffix Search List. . . . . . : PTS.local Ethernet adapter Local Area Connection: Connection-specific DNS Suffix . : Description . . . . . . . . . . . : HP NC362i Integrated DP Gigabit Server Adapter Physical Address. . . . . . . . . : 68-B5-99-B4-2C-A4 DHCP Enabled. . . . . . . . . . . : No Autoconfiguration Enabled . . . . : Yes Link-local IPv6 Address . . . . . : fe80::9d52:5f70:4118:461f%10(Preferred) IPv4 Address. . . . . . . . . . . : 192.168.16.2(Preferred) Subnet Mask . . . . . . . . . . . : 255.255.255.0 Default Gateway . . . . . . . . . : 192.168.16.1 DHCPv6 IAID . . . . . . . . . . . : 224966041 DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-14-CC-B9-E4-68-B5-99-B4-2C-A4 DNS Servers . . . . . . . . . . . : ::1 127.0.0.1 192.168.16.11 NetBIOS over Tcpip. . . . . . . . : Enabled Tunnel adapter Local Area Connection* 8: Media State . . . . . . . . . . . : Media disconnected Connection-specific DNS Suffix . : Description . . . . . . . . . . . : isatap.{CABA303D-1224-4DDD-99CD-89F56A010349} Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0 DHCP Enabled. . . . . . . . . . . : No Autoconfiguration Enabled . . . . : Yes Tunnel adapter Local Area Connection* 9: Media State . . . . . . . . . . . : Media disconnected Connection-specific DNS Suffix . : Description . . . . . . . . . . . : Teredo Tunneling Pseudo-Interface Physical Address. . . . . . . . . : 02-00-54-55-4E-01 DHCP Enabled. . . . . . . . . . . : No Autoconfiguration Enabled . . . . : Yes Workstation IPCONFIG: Windows IP Configuration Host Name . . . . . . . . . . . . : LT-ITAdmin01 Primary Dns Suffix . . . . . . . : PTS.local Node Type . . . . . . . . . . . . : Broadcast IP Routing Enabled. . . . . . . . : No WINS Proxy Enabled. . . . . . . . : No DNS Suffix Search List. . . . . . : PTS.local Ethernet adapter Local Area Connection 3: Media State . . . . . . . . . . . : Media disconnected Connection-specific DNS Suffix . : Description . . . . . . . . . . . : TAP-Win32 Adapter V9 Physical Address. . . . . . . . . : 00-FF-A0-48-6E-C8 DHCP Enabled. . . . . . . . . . . : Yes Autoconfiguration Enabled . . . . : Yes Ethernet adapter Local Area Connection 2: Media State . . . . . . . . . . . : Media disconnected Connection-specific DNS Suffix . : Description . . . . . . . . . . . : EasyTether Network Adapter Physical Address. . . . . . . . . : 02-00-54-74-68-72 DHCP Enabled. . . . . . . . . . . : Yes Autoconfiguration Enabled . . . . : Yes Wireless LAN adapter Wireless Network Connection: Media State . . . . . . . . . . . : Media disconnected Connection-specific DNS Suffix . : Description . . . . . . . . . . . : Intel(R) Centrino(R) Advanced-N 6200 AGN Physical Address. . . . . . . . . : 00-27-10-4E-39-2C DHCP Enabled. . . . . . . . . . . : Yes Autoconfiguration Enabled . . . . : Yes Ethernet adapter Local Area Connection: Connection-specific DNS Suffix . : PTS.local Description . . . . . . . . . . . : Intel(R) 82577LM Gigabit Network Connection Physical Address. . . . . . . . . : 88-AE-1D-AD-81-48 DHCP Enabled. . . . . . . . . . . : Yes Autoconfiguration Enabled . . . . : Yes Link-local IPv6 Address . . . . . : fe80::297a:5690:c793:c809%14(Preferred) IPv4 Address. . . . . . . . . . . : 192.168.16.81(Preferred) Subnet Mask . . . . . . . . . . . : 255.255.255.0 Lease Obtained. . . . . . . . . . : Wednesday, February 23, 2011 3:16:57 AM Lease Expires . . . . . . . . . . : Monday, March 07, 2011 3:17:00 AM Default Gateway . . . . . . . . . : 192.168.16.1 DHCP Server . . . . . . . . . . . : 192.168.16.2 DHCPv6 IAID . . . . . . . . . . . : 294170141 DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-14-6F-6C-6B-88-AE-1D-AD-81-48 DNS Servers . . . . . . . . . . . : 192.168.16.2 NetBIOS over Tcpip. . . . . . . . : Enabled Ethernet adapter Bluetooth Network Connection: Media State . . . . . . . . . . . : Media disconnected Connection-specific DNS Suffix . : Description . . . . . . . . . . . : Bluetooth Device (Personal Area Network) Physical Address. . . . . . . . . : 70-F3-95-82-C4-67 DHCP Enabled. . . . . . . . . . . : Yes Autoconfiguration Enabled . . . . : Yes Tunnel adapter isatap.{A0486EC8-AA6A-45E4-89EE-54250DC06208}: Media State . . . . . . . . . . . : Media disconnected Connection-specific DNS Suffix . : Description . . . . . . . . . . . : Microsoft ISATAP Adapter Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0 DHCP Enabled. . . . . . . . . . . : No Autoconfiguration Enabled . . . . : Yes Tunnel adapter isatap.{5D5974B5-C602-43A3-8C33-0725B5157EE3}: Media State . . . . . . . . . . . : Media disconnected Connection-specific DNS Suffix . : Description . . . . . . . . . . . : Microsoft ISATAP Adapter #2 Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0 DHCP Enabled. . . . . . . . . . . : No Autoconfiguration Enabled . . . . : Yes Tunnel adapter isatap.PTS.local: Media State . . . . . . . . . . . : Media disconnected Connection-specific DNS Suffix . : PTS.local Description . . . . . . . . . . . : Microsoft ISATAP Adapter #3 Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0 DHCP Enabled. . . . . . . . . . . : No Autoconfiguration Enabled . . . . : Yes Tunnel adapter Teredo Tunneling Pseudo-Interface: Media State . . . . . . . . . . . : Media disconnected Connection-specific DNS Suffix . : Description . . . . . . . . . . . : Teredo Tunneling Pseudo-Interface Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0 DHCP Enabled. . . . . . . . . . . : No Autoconfiguration Enabled . . . . : Yes Tunnel adapter isatap.{40A324E6-A2BB-4BA9-A97B-0485DCB2EF6D}: Media State . . . . . . . . . . . : Media disconnected Connection-specific DNS Suffix . : Description . . . . . . . . . . . : Microsoft ISATAP Adapter #4 Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0 DHCP Enabled. . . . . . . . . . . : No Autoconfiguration Enabled . . . . : Yes Tunnel adapter isatap.{D466B0E3-15C4-4C9B-92ED-A6D6B151BBD0}: Media State . . . . . . . . . . . : Media disconnected Connection-specific DNS Suffix . : Description . . . . . . . . . . . : Microsoft ISATAP Adapter #5 Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0 DHCP Enabled. . . . . . . . . . . : No Autoconfiguration Enabled . . . . : Yes

"DNS Servers . . . . . . . . . . . : ::1 127.0.0.1 192.168.16.11" In a windows domain it is critical that the server point only to your internal DNS servers, the ISP is added as a forwarder (or use root hints), and the client machines point only to your internal DNS server, for DNS name resolution. The only issues I see based on your ipconfig results are: -Is 192.168.16.11 an active secondary DNS server on your LAN? If not please try removing this and clear the cache. -Though the IPv4 and IPv6 local host addresses are acceptable for DNS, best practice usually recommends using the actual LAN IP of the serverRob