I have a newly migrated SBS 2011 server. I used the swing migration method and am having intermittent DNS issues.
I have a Dell 2970 Dual Quad with 32gig of memory. The DNS entry for the server NIC is the SBS server itself. My firewall is open out going.
I disabled one NIC so I'm using only one Nic as instructed. I can use the nslookup and resolve internal & external dns. The problem I have it when I browse to web sites, they come up sometimes, other times the same site doesn't load. I may get a time out, not found, partial site displayed with no graphics. If I click reload many times it usually comes up.
Before I decommissioned my swing tempdc, I was having the same issue, but changed the primary DNS server to the temp DC and the internet was fine. After the decommission, I am not able to reliably browse from the server or workstations. When using the DNS on the temp browser for the workstations, I still could not surf from the SBS server. I did change the IE restrictions for administrators, and I'm logged in as the domain administrator.
I've run dcdiag and it looks good. I've flushed DNS and registered dns. I've tried putting in valid forwarders in the dns. Just when I think it is working fine on 5-8 sites, it then seems to lose the ability to resolve and may display page not found or a partial web page. It could be on a page that was loaded many times like www.msn,com
. The last time I tested, it only loaded a partial page of MSN, and I immediately ran an nslookup on the server and it resolved.