[CentOS] Help with Intel 6235 Wireless on CentOS 7 (pointer to good reading?)

Wed Nov 25 19:44:39 UTC 2015
Valeri Galtsev <galtsev at kicp.uchicago.edu>

Dear Experts,

I would like to ask your advise on good reading about how to add WiFi
device, and how to control its settings on CentOS.

Sounds really dumb, but this is what I am NOT able to do on CentOS 7 what
I was able to do in the past, beginning somewhere since RedHat 5 or 6,
through Fedora and up to CentOS 6.

In brief: my card is Intel 6235; CentOS 7 (fully updatted), latest kernel
(3.10.0-229.20.1), relevant Intel firmware version for my card is in
/lib/firmware (together with large bunch of other Intel WiFi firmware),
relevant modules are loaded in kernel:


"/sbin/ifconfig -a" shows my device in the list renamed to wlp3s0
(according to PCI slot numbering I figure), dmesg shows device brought up
successfully detected and renamed as above. lspci shows device with its
correct full name (Network controller: Intel Corporation ... 6235"

Now comes the fun part (no, troublesome for me part). When I click on the
NetworkManager Applet in right top corner, there are no WiFi devices. I go
to Network Settings from there. My device is in the list under name "PCI
Unknown". I click on that, the device is described as "unmanaged", and
there is no way to make changes to the contrary to other devices (correct
MAC address is displayed).

OK, I assume I just need to declare device as NM_CONTROLLED. There is no
relevant /etc/sysconfig/ifcfg-wlp3s0 - where I know I can declare that. I
use "nmtui" to add configuration, then add to ifcfg-wlp3s0


line. Reboot. Still the same.

Just for comparison I booted Ubuntu 14.0.4 x86_64 live CD. Yes, it can see
my wireless, and I can connect to WiFi networks. Kernel is just a notch
newer ( which shouldn't matter according to Intel information
which kernel versions this device is supported in. List of relevant kernel
modules loaded by ubuntu is exactly the same. I don't see anything weird
like the need to separately load firmware as kernel module (yes, indeed
I'm going nuts, that would be "freebsd-ism" I guess).

I do not want to have Ubuntu (or Debian which likely will work out of the
box too) on this laptop. So, apparently I need a pointer to good reading
on how do we do it on CentOS 7 "dirty way" - when "click here, choose in
menu that" doesn't work.

Thanks a lot for your advises!


Valeri Galtsev
Sr System Administrator
Department of Astronomy and Astrophysics
Kavli Institute for Cosmological Physics
University of Chicago
Phone: 773-702-4247