10.6 NetworkManager and Security

NetworkManager distinguishes two types of wireless connections, trusted and untrusted. A trusted connection is any network that you explicitly selected in the past. All others are untrusted. Trusted connections are identified by the name and MAC address of the access point. Using the MAC address ensures that you cannot use a different access point with the name of your trusted connection.

NetworkManager periodically scans for available wireless networks. If multiple trusted networks are found, the most recently used is automatically selected. NetworkManager waits for your selection in case that all networks are untrusted.

If the encryption setting changes but the name and MAC address remain the same, NetworkManager attempts to connect, but first you are asked to confirm the new encryption settings and provide any updates, such as a new key.

NetworkManager knows two types of connections: user and system connections. If a connection is defined as System connection, it can be shared by all users and is made available during boot time—before any users log in. Such system connections can be used to automatically connect to networks that require authorization.

If you switch to offline mode from using a wireless connection, NetworkManager blanks the ESSID. This ensures that the card is disconnected.