[CentOS] CentOS 7.2 laptop wireless Intel Corporation Centrino Wireless-N 2230 (rev c4)

With CentOS 7.2 a laptop wireless card is recognized in dmesg, but
nonfunctional. Toggling the hardware wifi switch causes the Bluetooth
icon to appear and disappear. The network configuration window shows
the Wireless tab greyed out.  Rebooting with the bluetooth enabled
does not help. It appears the appropriate driver is iwlwifi, which is
what works in Fedora and appears to be available and installed in
CentOS.

lspci gives
08:00.0 Network controller: Intel Corporation Centrino Wireless-N 2230 (rev c4)

1. How do I get this working?  I am happy to work with command line tools.

2. Are there other packages I need? I installed wireless-tools, and
tried to fiddle with iwconfig and NetworkManager to no avail. iwconfig
does seem to interact with the wifi device.

3. Is there documentation I should be following to
understand/troubleshoot networking support?
https://wiki.centos.org/HowTos/Laptops/Wireless does not document the
iwlwifi driver.