Although ping
is most often used on its own, a number of switches can be used to assist in the troubleshooting process. Table 3 shows some of the commonly used switches with ping
on a Windows system.
Option |
Description |
---|---|
ping -t |
Pings a device on the network until stopped |
ping -a |
Resolves addresses to hostnames |
ping -n count |
Specifies the number of echo requests to send |
ping -r count |
Records route for count hops |
ping -s count |
Timestamp for count hops |
ping -w timeout |
Timeout in milliseconds to wait for each reply |
ping
works by sending ICMP echo request messages to another device on the network. If the other device on the network hears the ping
request, it automatically responds with an ICMP echo reply. By default, the ping
command on a Windows-based system sends four data packets; however, using the -t
switch, a continuous stream of ping
requests can be sent.
ping
is perhaps the most widely used of all network tools; it is primarily used to verify connectivity between two network devices. On a good day, the results from the ping
command will be successful, and the sending device will receive a reply from the remote device. Not all ping
results are that successful, and to be able to effectively use ping
, you must be able to interpret the results of a failed ping
command.
The Destination Host Unreachable Message
The Destination Host Unreachable error message means that a route to the destination computer system cannot be found. To remedy this problem, you might need to examine the routing information on the local host to confirm that the local host is correctly configured, or you might need to make sure that the default gateway information is correct. The following is an example of a ping
failure that gives the Destination host unreachable
message:
Pinging 24.67.54.233 with 32 bytes of data: Destination host unreachable. Destination host unreachable. Destination host unreachable. Destination host unreachable. Ping statistics for 24.67.54.233: Packets: Sent = 4, Received = 0, Lost = 4 (100% loss), Approximate round trip times in milli-seconds: Minimum = 0ms, Maximum = 0ms, Average = 0ms