Howard Owen (hbo(a)egbok.com) said:
Why not configure portmapper to listen on localhost, then have the
services (mountd, ypserv, etc.) that need it enable listening on the
wire when they start? You'd need a cooperative arrangement whereby the
init scripts would shut down external portmapper if they were the last
service that needed it on service shutdown.
Having 'mount' try and configure services would be exceedingly messy.