How to solve the problem of waiting for network after ubuntu 12.04 is restarted

After ubuntu 12.04 is restarted, how does one enable waiting for network to access the Internet wirelessly in a notebook under ubuntu? The configuration steps are mainly two steps, one for wireless connection (enter the Key ), one step is used for dialing (enter the bandwidth account and password ). 1. wireless connection right-click the network connection icon on the panel, select Edit connection, select wireless in the open network connection window, click Add, enter the key, and select automatic connection, however, in ubuntu 12.04, if you use the sudo pppoeconf command to configure dialing, the system displays waiting for network configuration after you restart the computer, then, waiting up to 60 more seconds for network configuration is displayed, and the booting system without full network configuration is displayed. after entering the desktop, the network connection status icon disappears. Cause: When the sudo pppoeconf command is used, information is written to the/etc/network/interfaces file, which directly causes the above problem. Solution: After the sudo gedit/etc/network/interfaces file is opened, delete all the content except auto lo iface lo inet loopback and restart the system.