Hi I have server running 2008R2 hosting my DHCP and DNS, I have a littile problem with my DNS server, my network is running fine but once a week all my client complains that they cannot access any web sites, If I then go to my DNS server and clear the cash everything is back to normal for antoher week. I have tried to setup DNS forwarders to my ISP dns server, but my server cannot resolve my ISP DNS server so I don't use that, the funny thing is that if i let my Sonicwall handle the DHCP and DNS there is no problem at all and i can resolve my ISP DNS. I don't know if that has anything to do with my problem clearing the DNS cash Can any one help me in the right direction, Dou Core

Yes, this is the problem. Are you saying you can't ping ISPs DNS servers from your server? What are internet connection details? Regards, Dave Patrick .... Microsoft Certified Professional -Microsoft MVP [Windows]

Hi I can ping my ISP's DNS server by IP adresse but I cannot resolve the IP adress. I found this i another post http://weblogs.asp.net/owscott/archive/2009/09/15/windows-server-2008-r2-dns-issues.aspx and now I can resolve my ISP IP adresses and I can use forwarders so I hope this has solved the problem Dou Core

There really isn't anything to resolve. Basically your DHCP server must hand out static address of AD server as primary DNS server address so clients can find DC. Then put the ISP's DNS addresses in the forward lookup of your DNS server so clients can find internet. Also make sure your server has static IP address outside of DHCP scope. Installing Active Directory on Windows Server 2008 http://www.petri.co.il/installing-active-directory-windows-server-2008.htm Please post back with any specific questions. Regards, Dave Patrick .... Microsoft Certified Professional -Microsoft MVP [Windows]

hi, Please post unedited ipconfig/all output from one ofyour a) failing client b) primary dns server. Also you have to have ISP dns server under your forwarder tab. A best way to troubleshoot the issue is to capture a netmon / ethereal trace when clients are experiencing problem.