Using Advanced Tools Getting Started Guide 117 The ping command The ping command checks that a network connection can be established between your computer and another computer. To use the ping command, enter ping with the name or IP address of another computer. You can use ping within your local network to check your Ethernet connection; you can also use ping to check that your connection to the Internet is active. When using ping to check for networking problems, follow this order of testing: • Use this command to establish that networking within your own computer is activated: ping localhost • Use a ping command with an IP address to establish that your Ethernet card is functioning (you can even start with the IP address of your own system to see that the Ethernet interface is configured). For example: ping 207.179.18.1 • Use a ping command with a host and domain name to establish that your DNS server is resolving domain names into IP addresses for you. For example: ping www.calderasystems.com The ifconfig command Another useful command is ifconfig. This command is used behind the scenes by the Coas and lisa utilities to establish your networking within the Linux kernel, based on the IP addresses and other information that you provide. You can enter the ifconfig command without any parameters to see a list of your current network interfaces: ifconfig You can also use ifconfig with various command line parameters and options to manually complete any of the following tasks: • Add IP aliases to a single Ethernet card • Bring up or take down any network interface, such as the localhost test interface, or your eth0 Ethernet interface • Define your gateway address, network mask, and so forth.