To check host reachability and network connectivity, use the ping exec (user) or privileged exec command. After you log in to the router or access server, you are automatically in user exec command mode. The exec commands available at the user level are a subset of those available at the privileged level. In general, the user exec commands allow you to connect to remote devices, change terminal settings on a temporary basis, perform basic tests, and list system information. The ping command can be used to confirm basic network connectivity on AppleTalk, ISO Conectionless Network Service (CLNS), IP, Novell, Apollo, VINES, DECnet, or XNS networks.
For IP, the ping command sends Internet Control Message Protocol (ICMP) Echo messages. ICMP is the Internet protocol that reports errors and provides information relevant to IP packet addressing. If a station receives an ICMP Echo message, it sends an ICMP Echo Reply message back to the source.
The extended command mode of the ping command permits you to specify the supported IP header options. This allows the router to perform a more extensive range of test options. To enter ping extended command mode, enter yes at the extended commands prompt of the ping command.
It is a good idea to use the ping command when the network is functioning properly to see how the command works under normal conditions and so you have something to compare against when troubleshooting.
For detailed information on using the ping and extended ping commands, refer to the Cisco IOS Configuration Fundamentals Command Reference.
Was this article helpful?
Read how to maintain and repair any desktop and laptop computer. This Ebook has articles with photos and videos that show detailed step by step pc repair and maintenance procedures. There are many links to online videos that explain how you can build, maintain, speed up, clean, and repair your computer yourself. Put the money that you were going to pay the PC Tech in your own pocket.