I work for a school that is running SBS2003. The school has two subnets, one behind the SBS for staff and another isolated lab behind a firewall/router. The lab has absolutely no issues whatsoever, yet the internet access behind the SBS is very unreliable. Behind the SBS the clients get many timeouts and dns errors and have to try urls several times sometimes before they will load up the pages. I have tried to bypass the SBS DNS and use an external DNS server, but that has not helped the issue. Could anyone advise as to where I might start looking?