What if you're not able to connect to the Internet at all? Thankfully, networking issues are rare in Linux nowadays, but in case you do experience an issue connecting, there are some things you can do in order to pinpoint the problem.

First, check to see if you have an IP address. To do so, execute the ifconfig command, and look for either eth0 (which represents your Ethernet card) or wlan0 (which represents your wireless card). The naming convention can be different, so don't worry if you see neither declaration. The following screenshot shows the output from the ifconfig command:

If you see an IP address listed, you should be connected. However, if you don't, you may want to check your /var/log/dmesg log for messages specific to eth0 or wlan0 depending on what you're connecting with. If you see log entries mentioning timeouts when trying to acquire an IP address from your DHCP server, your issue may simply be that your clock is wrong...