I have a active/active SQL cluster with each server also running as a domain controller and DNS server (not the best situation, but due to limited servers in the location where these machines sit there wasn't another option but to do this). I am now entercountering some DNS issues. DNS records for these SQL servers, the cluster, etc.do not seem to populate from Active Directory where I can see they exist into the DNS Service itself (this is a Active-directory integrated DNS zone). I'll be using the NETDIAG tool from Microsoft to try to resolve this issue. That really isn't really an issue for this forum, but it brings up a question about DNS and clusters in general. I have added hosts files that contains all the host records for the cluster,etc. to all my other Windows boxes since they cannot rely on the internal DNS servers that are not running properly. At this time the cluster and SQL and access are working fine even though the internal DNS servers do not. My concern is that I may have to recreate a new DNS zone or reinstall DNS if I cannot recover the existing zone that does not populate properly. I am waiting to do this on off-peak hours. This would mean there would be a period of time where there is no DNS server (which is technically what I have now anyways, but I wonder if the cluster is using any cached info). What problems will this cause if any on the cluster having no DNS server for a short period while it is rebuilt? Does the cluster service or SQL instances use DNS and require it to run? IN terms of TCPIP settings, each clustered server points to themselves for primary and the other clustered server for secondary DNS. I could add the same hosts file to these machines as well. Sorry if it is a bit off topic.