we have only one domain controller(Win 2K3 R2) in our organization (eg: dc1.abc.com - 10.10.10.4)...we are not using dc for recursion process.. our client dns settings are primary dns server : 10.10.10.4 secondary dns server : ISP dns server all clients are able to connect to the internet using ISP dns server.. recently we have deployed new exchange 2007 server.. we have applied same DNS Setting for exchage server also.. we are using both external and internal domain names are same (abc.com) but it is giving an error could not find any domain controller in abc.com without configuring ISP DNS server as secondary dns server exchange server it is working fine..i have tested..but unable to connect internetMCITP

Your DNS is not configured properly. Have all clients point to your DNS server only, and configure your server to use root hints for Internet zones. If, for some reason, you can't use root hints, then have your server point to the ISP DNS server as a forwarder. The problem is that if Windows clients look to the ISP DNS server, it won't point back to yours for Active Directory records they need to find.Ed Crowley MVP "There are seldom good technological solutions to behavioral problems."

is that best practice to have same domain name for both domains(external and internal)...we have only one domain controller ..may be in future we can one more adc ...in exchange environmentMCITP

Having the same internal and external domain name makes a lot of things simpler, like configuring Exchange certificates and teaching your users which URLs to use. From that standpoint, it's best practice, but plenty of organizations have configured .local domains and the like for internal use. Personally, I think configuring split-brain DNS is so easy that I can't imagine why anyone would use different zones internally than externally.Ed Crowley MVP "There are seldom good technological solutions to behavioral problems."

Please run nslookup command and check DNS is function. And check your default gateway IP setting. G. P. Namal Nandana Subasinghe, Email: - gpnamal@hotmail.com or gpnamal@gmail.com , gpnamal@yahoo.com Mobile: - +974-55753704 Street No 50, Gate No 149, Industrial Area -Doha, Qatar.