Lots of folks use NetworkManager or wicd without realizing wpasupplicant already has a decent GUI (and CLI) for managing wifi networks. To use it effectively you have to configure wpasupplicant for roaming, but not only is that pretty easy to do, it’s well documented (on Debian systems, in /usr/share/doc/wpa_supplicant/README.Debian.gz).
Why not just use NetworkManager or wicd? A few reasons:
- NetworkManager is huge, and requires large bits of either KDE or Gnome in order to use the GUI. Since I’m using i3wm, I don’t really want to fill my disk up with a bunch of Gnome stuff simply to connect to wireless.
- wicd is crufty and janky.
- Both NetworkManager and wicd have bugs where they can’t scan or connect in environments that have large numbers of access points.
That last one is the killer for me. At work there are many dozens of visible access points in most areas, and both NetworkManager and wicd can’t cope.
Setting up wpasupplicant for roaming requires editing a couple of files to enable it, but actual access point configuration is done via wpa_gui or wpa_cli as you prefer.
Modify /etc/network/interfaces so your wireless interface looks like:
auto wlan0 allow-hotplug wlan0 iface wlan0 inet manual wpa-roam /etc/wpa_supplicant/wpa_supplicant.conf iface wlan0 inet dhcp iface wlan0 inet6 auto
And create /etc/wpa_supplicant/wpa_supplicant.conf, making sure it’s owned by root and chmod 600:
ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev update_config=1
Don’t forget to add yourself to the netdev group as needed.
Now, use wpa_gui (or wpa_cli if you wish) to scan and configure your wireless networks.
The wpa_supplicant.conf will have plaintext passwords - some people consider this an issue, but since all my laptops use LUKS encrypted volumes, it’s no risk for me in a powered off system. And if someone did compromise a running system they could certainly see the key if they had root access - but I can also steal that directly from wpasupplicant on a running system with NetworkManager or wicd. So, in summary - there is no additional risk in using wpasupplicant directly on a properly secured system.
Update 2015-02-08: See here for an update for the following, which automates this so manually restarting the interface is no longer necessary.
wpasupplicant manages wifi, but not dhcp (where NetworkManager and wicd handle both). Sometimes, this means I don’t get an ipv4 DHCP address until I restart dhcp. Although I only need to stop and restart dhclient, I tend to prefer using ifup since it’s less to type:
$ sudo ifup wlan0
Eventually I’ll modify wpasupplicant’s postup action to do this automatically, but I don’t find this that big of a deal - certainly no worse than having to manually disconnect/connect to access points that you end up having to do with NetworkManager anyway (and in other operating systems - I see MacOS users having to do this constantly).