ARCHIVED: In Mac OS, how can I check to see if a computer is on the network?

The information in this document doesn't apply to Mac OS X. For information on how to do this in Mac OS X, see ARCHIVED: In Mac OS X, how can I check to see if a computer is on the network?

To see if a computer is on the network, you will need a utility that is capable of pinging the remote host. A ping is a small packet of data sent to the remote host and then sent back by the recipient computer. If the computer is no longer on the network, it will not be able to respond to the packet.

There are a number of programs that you can use to ping a computer in Mac OS. Three of the more powerful applications are IPNetMonitor, WhatRoute, and Interarchy. They are not only able to ping a computer, they are also able to trace the route data takes as it travels between your Mac and the other computer. Thus, they are able to pinpoint fairly accurately where on the network the connection between your computer and the recipient computer has failed. All three programs require a connection to the Internet. IPNetMonitor and WhatRoute are shareware, while Interarchy is a commercial product. For more information, visit the following web pages:

• IPNetMonitor: Requires Mac OS 7.5.3 or higher and Open Transport 1.1.1 or better; available from Sustainable Softworks.
• WhatRoute: Requires Mac OS 7.5.3 or higher and Open Transport; available from the WhatRoute Page.
• Interarchy: Requires Mac OS 7.6.1 or higher, Open Transport 1.1.1, and a PowerPC processor

In some cases a computer will respond to a ping but will be unreachable by other network tools such as telnet, rlogin, or web browsers.