This enhancement to NetworkManager will enable easy-to-use AP-mode for supported hardware, which solves compatibility problems and provides a smoother user experience.
- Name: Dan Williams
- Email: dcbw at redhat dot com
- Targeted release: Fedora 18
- Last updated: 2012-05-30
- Percentage of completion: 30%
NetworkManager currently uses AdHoc (IBSS) mode for Internet Connection Sharing via WiFi. While compatible with all wifi cards, this mode has some limitations. The kernel does not work reliably in WPA/WPA2 Ad-Hoc mode, leading to supposedly secure networks being created as insecure ones. Second, AdHoc mode does not work as reliably as Infrastructure/AP mode becuase there is no central coordinating entity (like an Access Point) to enforce authentication and act as a traffic manager. Third, many consumer devices like smartphones and tablets do not allow connections to AdHoc networks on the premise that since anyone can create one, they aren't secure and could be used for phishing unsuspecting users.
Benefit to Fedora
This feature will provide a smoother Internet Connection Sharing/Hotspot feature for users that actually works in most cases.
Many kernel drivers support AP mode, and wpa_supplicant has a "lightweight hotspot" mode that NetworkManager will utilize. NM already checks to see if the wifi card supports AP mode, so the rest of the job is to push the correct configuration options to wpa_supplicant when Internet Connection Sharing is started. This change is not invasive.
How To Test
We need to get a good list of WiFi cards that support AP mode; not all do. Specifically, devices older than a few years are unlikely to support AP mode, and any driver that does not use the kernel's mac80211 stack will not be supported (ie, really old drivers like airo, orinoco, etc and binary drivers like wl.o). Furthermore devices may require updated firmware to support AP mode (specifically, Intel devices). You can check if your device supports AP mode by running "iw list" and looking in the 'Supported interface modes' section for "AP". See: http://linuxwireless.org/en/users/Drivers for AP support.
By default newly created Hotspot connections will use AP mode. There will be no difference in the existing user interaction to create a hotspot. Existing hotspot configurations will continue to use AdHoc mode unless explicitly changed to AP mode.
This change depends on wpa_supplicant 0.7.3 or greater, which we ship in Fedora 15 and later.
If the feature cannot be completed, we will simply disable it with no user impact and remain with the existing AdHoc mode only.
- No documentation at this time
- NetworkManager now supports an enhanced Hotspot/Internet Connection Sharing mode for WiFi, which enables a much smoother connection sharing experience and is better supported by hardware. This mode is automatically enabled only for newly created connection to ensure existing configuration is unchanged.