Does RPM support the “do-not-fragment” bit
Can you set the do-not-fragment bit for RPM probes
RPM does not support setting the do-not-fragment bit
However you can use the following work-around:
You can configure a FW filter which drops RPM reply packets if they come back fragmented thus forcing probe reply loss if it crosses link with wrong MTU. Of course, this might give some false results where forward probe is fragmented but reply is not.