Hi,
We have a strange problem with DNS Service in our company. When numerous http connection opened in one machine,
DNS service of the server (Windows 2008 R2) blocks external network (actually browsing), even I try to connect with static IP and another DNS server, connection fails (for all web connections - url doesn't matter).
When DNS service stopped, by changing DNS server settings, we can connect.
I have checked DNS server settings, nothing seems wrong and ther is no error at DNS logs. However, I am not sure that DNS server is the cause of problem, because ping cannot response properly (some queries succeed, some of them fail ) with external IP's , not only urls --and all happens when DNS service is started
Also, the server is mail server at the same time , there is no problem at internal-external mail traffic, whether DNS service is open or not, it works normally.
Any help would be greatly appreciated,
Thanks in advance,