Trace statements are macros which are only active in DEBUG mode
(see Section ). If you are writing a new protocol,
you should insert trace statements. Even though there will be no
bugs left after you release your protocol, it may help others in
debugging their protocols. Don't delete these very helpful
debugging statements when you are done.
The trace levels listed in Section are in
increasing order of severity. When an runs with tracing
enabled, trace statements associated with a trace variable will print
if their trace level is at least as severe as the value of the trace
variable. For example, if the TCP trace variable is set to
TR_GROSS_EVENTS, this will cause TCP trace statements with trace
levels of TR_GROSS_EVENTS, TR_ERRORS and
TR_ALWAYS to be displayed. To display all TCP trace statements, you
would set the TCP trace variable to have the value
TR_FULL_TRACE.