I have a MacBook Pro (13-inch, Mid 2012) MacOsX Sierra 10.12.3 (16D32) and I have a weird issue with my office's WLAN: I can connect to WiFi, and navigate on internet, then (usually after around one minute) it stops working: I'm still connected (the top-right icon shows the wifi interface it's still on and connected to the network), but pages don't load anymore and request end up in timeout errors. If I turn WiFi off and on again everything works again for a while then it stops and I have to turn wifi off/on again. So the loop takes place.
I can't figure out what the problem is and isolate it, everything seems ok. I guess this is likely a network (router) problem, since it only happens at work, but my colleagues apparently don't have this problem. Plus, if it were a routing problem, why does everything works again after a simple wifi interface reconnection laptop side i.e. without doing anything router-side?
EDIT: I've done some test and it turns out after apparently loosing connectivity to internet it's still possible to ping public hosts. So, I guess, network is up, DNS work correctly, and the problem should be limited to http data forwarding on port 80 (so, likely a routing problem)