If you have issues like that, chances are you have an ip conflict. Rebooting or reconnecting fixes that yes, but fixing the root cause would be more helpful - ie make sure that 'range extender' of whatever type is set up properly and not handing out ip adresses in a range that is/could be used elsewhere in the network.
Especially if you use a router as an 'extender' and have not disabled that one's DHCP, things in your network get... interesting... from time to time.