Network Configuration - Raspberry Pi User Guide - page 62

To make sure that the network is operational, unplug the Pi's Ethernet cable (if attached)
and type the following:

ping -c 1 www.raspberrypi.org

If you start having problems with your Pi following the installation of a USB wireless adapter, it
could be due to a conlict with other USB devices. Some adapter models are known to cause
problems with certain USB keyboards. For an up-to-date list of adapters that are known to be
good, as well as those that are known to cause conlicts, visit http://www.element14.
com/community/docs/DOC-44703/l/raspberry-pi-wifi-adapter-testing or the
eLinux wiki at http://elinux.org/RPi_VerifiedPeripherals#Working_USB_Wifi_
Adapters .

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