No website opening but network works perfect, dns perfect as well I am relatively new to OSX but I do my best here. I read a lot and tried to solve but did not find a answer which fits to my problem well.

I have a Mac Mini with Yosemite 10.10.2. My network seems perfect and I can ping for example in my Terminal any website, domain etc. also nslookup works perfect for any domain. 

How ever if I try to open a website nothing opens and the page loads simply forever. I am connected either with Wifi or Cable but the same result. I tried to activate/disactivate  without success the network adapter. Of course I restarted modem as well. (Besides with my tablet and phone the same modem via Wifi works perfect).

I dont know what else to do. I also do not use any Antivirus, Firewall etc. software in this moment. How ever something blocks me from opening any website. the only thing which helps me is a complete restart of my system.

Thank you  in advance for any tip.
Check to see if your time and date are set correctly. Safari will have all sorts of trouble including with certificates when the time is off.