Since Tuesday until now. 3 days already, we have problem with my proxy server (IPCOP). User cannot access website (HTTP/HTTPS) / can access but very slow until error in some period, but Skype can use as normally. I tried to check on both IPCOP and Firewall already. On IPCOP can ping to internet as usual but why user cannot access / can access but very slow?. On Firewall, I saw in 'Server Farm' policy, don't have any traffic log (It should have. Right?). Can you guidance me it caused from what?