The Ping Diagnostic Utility

You are probably familiar with the ping utility from Windows or Linux. The version included with the Cisco IOS provides significantly enhanced functionality, and can be used to test connectivity for a variety of different protocols including IP, IPX, AppleTalk and more. To get a sense of the functions provided by ping, issue the ping command followed by the question mark.

cisco2501#ping ?
WORD Ping destination address or hostname
appletalk Appletalk echo
decnet DECnet echo
ip IP echo
ipx Novell/IPX echo
tag Tag encapsulated IP echo

Notice the range of protocols that ping can work with. In fact, the list can be even longer depending on the protocols supported by your IOS version. At the most basic level, ping sends out echo request messages and expects to receive back echo replies. It is important to be clear about the information that a ping provides. For example, if you can ping an IP host on a different network, it suggests that both hosts have TCP/IP correctly initialized and configured, and that routing between the networks is also configured correctly. In cases where you cannot ping a remote host, don’t jump to the conclusion that the remote host is unavailable or misconfigured – though it might be, the problem may also be a configuration issue with the source host, or potentially some routing-related (or physical connectivity) issue between the two. As a general rule, use the following steps to determine the source of connectivity issues between your PC and a remote system:

  1. Assuming that your IP address, subnet mask, and default gateway are correct, attempt to ping a host on a different subnet. If this fails, one possibility is that routing is not configured correctly.
  2. If pinging a remote host fails, attempt to ping your default gateway. If this fails, it may indicate that TCP/IP is not configured correctly on your local router interface, on your host PC, or that the router interface has not been enabled with the no shutdown command.
  3. If pinging your default gateway fails, try pinging your host’s configured IP address. If this fails, it can may mean that you have configured your host PC’s IP address incorrectly, or that TCP/IP is not properly installed or initialized on the host system.
  4. If pinging the host’s IP address fails, try pinging the loopback address – If this fails, it generally indicates that TCP/IP is not properly installed or initialized on your host system.

To test IP connectivity, use the ping command followed by a hostname or IP address.

cisco2501#ping accra
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to, timeout is 2 seconds:
Success rate is 100 percent (5/5), round-trip min/avg/max = 4/4/4 ms

The ping was successful in this case, as illustrated by the five exclamation points and the final statement. In cases where a ping fails, you’ll see a message similar to the one shown below.

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to, timeout is 2 seconds:
Success rate is 0 percent (0/5)

When the exclamation points are replaces by dots, it means that for whatever reason, the destination host did not respond successfully. Again, this could suggest a range of issues including misconfiguration, physical network issues, routing problems, and so forth.

An extended ping allows a higher degree of control than the default ping settings, including the ability to change the repeat count, size of the datagrams, and so forth. The example below outlines an IPX ping using the extended ping interface.

Protocol [ip]: ipx
Target IPX address: 101A.0060.5cc4.f41b
Repeat count [5]:
Datagram size [100]:
Timeout in seconds [2]:
Verbose [n]:
Type escape sequence to abort.
Sending 5, 100-byte IPXcisco Echoes to 101A.0060.5cc4.f41b, timeout is 2 seconds
Success rate is 100 percent (5/5), round-trip min/avg/max = 4/5/8 ms

Although generally a TCP/IP utility, ping works with a number of protocols beyond IP and IPX. For a complete list of the protocols that ping supports on your router, issue the command ping ?.

Author: Dan DiNicolo

Dan DiNicolo is a freelance author, consultant, trainer, and the managing editor of He is the author of the CCNA Study Guide found on this site, as well as many books including the PC Magazine titles Windows XP Security Solutions and Windows Vista Security Solutions. Click here to contact Dan.