Specifications

STP and MSTP debugging enhancements (CR00016978) 162
Version 291-18
C613-10488-00 REV Q
STP and MSTP debugging enhancements (CR00016978)
Debugging command and output enhancements
STP and MSTP debugging have been enhanced in the following ways:
■ A new STP and MSTP debugging option turns on real-time switch port state debugging. This option displays a message every time STP/MSTP asks for the
state of a port to be changed. To enable the new debugging, use one of the commands:
enable stp[={stp-name|ALL}] debug=swi
enable mstp debug=swi
The output takes the form “<timestamp> <port> <new state>”. For example, the output “13:37:47/6.4/Discarding” shows that port 6.4 moved in to the
discarding state at 13:37:47.
■ New switch debugging options report the same output as the new STP/MSTP debug option, but displays the output when the STP/MSTP state changes
within the switching module, instead of within the STP/MSTP module. Therefore, the STP/MSTP debugging shows the change that STP/MSTP asked for
and the switch debugging shows the change that switching made. These two changes should be compatible. To enable the new switch debugging, usethe
command:
enable switch debug={stp|mstp}
■ A new tconly parameter limits message debugging so that an incoming or outgoing message is only displayed if it is a topology change message (the TC-
flag is set within the message). This is useful when debugging IGMP topology change notification. To turn this feature on and off, use one of the commands:
enable stp[={stp-name|ALL}] debug=msg tconly={on|off|yes|no}
enable mstp debug=msg tconly={on|off|yes|no}
The default is off.
■ All STP and MSTP debugging output is now time-stamped.