Rpcbind

rpcbind universal addresses to RPC program number mapper. Listens on TCP and UDP port 111 and distributed in rpcbind package in Ubuntu and Debian.

apt-cache rdepends rpcbind
...
monitoring-plugins-standard
...

See also: Nagios

systemctl stop rpcbind
Warning: Stopping rpcbind.service, but it can still be activated by:
  rpcbind.socket