I am on Ubuntu 15.04 using xfce (xubuntu) and am having trouble with my wi-fi. The indicator continues to show that I am connected to the network but after some amount of time I will no longer have internet access. In order to fix the issue I simply disconnect from the network and reconnect which always resolves it. I have had this issue occur on different networks.
03:00.0 Network controller : Intel Corporation Centrino Advanced-N 6205 [Taylor Peak] [8086:0085] (rev 34) Subsystem: Intel Corporation Centrino Advanced-N 6205 AGN [8086:1311] Kernel driver in use: iwlwifi