Hi,
we have still some few packages which install scripts in /etc/sysconfig/network/if-{down,up}.d
With a fresh default installation, scripts in this directory will not be executed anymore!
Additional, 2/3 of the scripts I looked at until now are broken and don't work since years, one could even have never worked after an analysis together with todays package maintainer.
So, if you have such a script, please look careful on it if it is really needed (which is questionable as it doesn't get executed anymore) and if yes, please port it to NetworkManagers dispatcher.d and drop the old one.
Thorsten