PupTool is mainly menu driven, the only other input needed being a name or address string. This is provided by clicking the button marked "Name or Address" and typing in the required string. There is a window below this button in which error messages are printed.

The menu item "EchoOn" causes Echo-Me Pups to be sent to the given host. Most servers respond to such Pups by sending back a copy of the Pup data to its source in an I-Am-Echo Pup. Echo-Me Pups are sent in lengths ranging from the minimum to the maximum allowed and containing a distinctive data pattern. Each Echo-Me Pup causes a character to be printed in the Puptool text window. The character "!" indicates a successful echo, while the character "#" means that the returning Pup was out of sequence (i.e. late). The character "~" says that the data field of the I-Am-Echo did not match that of the Echo-Me, while the character "x" indicates that a non Echo-Me Pup arrived (the contents of this Pup will be displayed in the error window). Finally, if no Pup arrives within the timeout period of 2 seconds the character "?" will be printed.
 
Clicking "EchoOff" stops the echo test and prints a summary of the various Pups sent and received.

Clicking this menu item will produce a routing table to hosts on remote nets from the local net. Each entry in the table has the form:
 
Remote net # | local gateway used for that net | number of gateways on route
  

Clicking the menu item "GetName" or "GetAddress" will cause the string in the Name or Address field to be converted to an internet name or address. Typical name strings which might be given are "ivy", "ivy+echo", "parc-nets3+cabernet+mail", "clover+12" etc. Typical address strings are "3##" (net 3), "3#121#", "3#121#234" etc.