I have a strange problem.
2008 R2 domain and windows 7 clients. Simple network. Switch connected to Firewall connected to ADSL router.
Clients can ping websites but not display in browsers.
What I've tried:
Checked firewall has outbound rule for HTTP, DNS, HTTPS,
NSLOOKUP returning correct info, pings alive from firewall and clients.
enabled DNS logging and no errors.
Flushed DNS on clients. Tried setting DNS to googles to bypass internal but no change.
...next thing to try is connect laptop onto ADSL router, configure NIC as secondary WAN IP and check connecting directly to the internet from there.
Any other suggestions to try? very weird!