by Matthew G. Naugle
Wiley Computer Publishing, John Wiley & Sons, Inc.
ISBN: 0471196568 Pub Date: 11/01/98
|
|
Illustrated TCP/IP
by Matthew G. Naugle Wiley Computer Publishing, John Wiley & Sons, Inc. ISBN: 0471196568 Pub Date: 11/01/98 |
| Previous | Table of Contents | Next |
Ask anyone involved in troubleshooting an IP network and he or she will tell you the most-used application is the PING application—one of the most common uses for ICMP is the PING program. Ping (not originally named, but commonly called Packet Internet Groper) is an ICMP message that tries to locate other stations on the internet to see if they are active or to see if a path is up. PING is an echo program. The originator of a datagram sends a PING request and the destination station should echo this request. Information can be contained in the PING datagram, which the destination station should echo. PING has the following format (using Windows 95):
Usage
ping [-t] [-a] [-n count] [-l size] [-f] [-i TTL] [-v TOS] [-r count] [-s count] [[-j host-list] | [-k host-list]] [-w timeout] destination-list
Options
| -t | Ping the specified host until interrupted |
| -a | Resolve addresses to hostnames |
| -n count | Number of echo requests to send |
| -l size | Send buffer size |
| -f | Set Don’t Fragment flag in packet |
| -i TTL | Time to Live |
| -v TOS | Type of Service |
| -r count | Record route for count hops |
| -s count | Timestamp for count hops |
| -j host-list | Loose source route along host-list |
| -k host-list | Strict source route along host-list |
| -w timeout | Timeout in milliseconds to wait for each reply |
Notice that you can test many things along the path to a destination using the PING command; for example, timing, source route, route recording, and data. Another use of the PING command is to check for network delays along a path. The response to a PING request can report the response delay (usually measured in milliseconds).
A lot of network management software uses this command to determine the status of a given station. Network management software will build maps to show the topology and placement of network stations. Using colors (green for active, yellow for possible errors, and red for not responding), a network manager can trace problems on the network. A lot of the work is done through the use of the PING utility.
| Previous | Table of Contents | Next |
)