Pining for a Pinger
- 31 March, 1999 21:49
ISPs conserve their resources by logging off connections that have been idle for a while. A Ping utility keeps your Internet connection alive.
Ping (packet Internet groper) is a standard TCP/IP utility used to query an Internet host (any machine on the Internet is called a host) and ensure that it is possible to establish an active connection. It's a form of cyberforeplay, equivalent to saying "You awake?"
If you Ping continually, you fool your ISP's system into thinking the connection is always in use and avoid being logged off. However, just as repeated wake-up calls may annoy, Pinging continually is Internet-antisocial. If you're paying for time online, rather than for a fixed price connection, you may find it expensive to keep the line open. If you're paying a fixed price with an additional cost for download traffic, you may end up paying more if you don't limit the traffic your Pinging generates.
Windows 9x comes with a simple command line Ping utility. To use it you simply start up an MS-DOS session (Start-Programs-MS-DOS Prompt) and type:
whereis either the IP address (eg 184.108.40.206) or the domain name (eg pcworld.idg.com.au) of the machine you wish to Ping. Type Ping with no argument to see a full set of options.
Ping attempts to send a packet to the machine and receive an echoed packet in return, and displays the time taken for the round trip. If it fails to receive a packet in reply, Ping displays an error message: "Bad IP address" indicates you used a domain name that cannot be resolved, and "Timed out" indicates no reply arrived before the timeout period elapsed. If it fails all four times, someone has a headache. This could be the TCP/IP software on the local or remote machine, or some part of the network in between.
Not only does Ping tell you if the destination machine is talking to you, it measures with the time value the sluggishness of the network connecting you. TTL (Time to Live) is a setting that determines an upper limit on time and router hops before the packet times out.
The Ping option -t causes the utility to Ping a specified address until interrupted. If you don't interrupt Ping, it should keep the connection alive permanently. With this Ping utility, there is no option to limit the traffic, and this may result in a cost.
You can create a batch file containing the Ping -tcommand, and place a Shortcut on your desktop. For an address you can use your ISP's Web or mail server name.
Manually start the batch file after you start your dial-up connection. You could place the Shortcut in your Windows startup folder and have it permanently running, but this is a waste of computer resources. When you're not connected to the Internet, a goodly portion of your CPU cycles will be devoted to creating the message: "Destination host unreachable".
For more functionality and a graphical interface, try the WS_Ping Pro Pack, a Windows 95/NT program offering not only Ping but traceroute, name server lookup, finger, whois, LDAP, quote, scan, SNMP and WinNet (see our cover CD). It also lets you query HTML headers and synchronise your system with world standard digital clocks such as the US Navy Clock. A 30-day evaluation version is available at www.ipswitch.com and the single user purchase price is $US37.50 - not bad for a professional network diagnostic utility. WS_Ping has context sensitive online help explaining in detail all the tools it provides, including Ping. By setting the delay to 60 seconds you limit traffic, and by setting the repeat count to 9999 you keep the connection open.