RHEL7: rpcbind listens on ports tcp/111 and/or tcp6/111 while it should not

Issue

• On boot, rpcbind listens on port tcp6/111 while it should not (systemd is supposed to listen on this port)

  # netstat -anlp | grep -w -e 111 | grep LISTEN
  tcp        0      0 0.0.0.0:111             0.0.0.0:*               LISTEN      1/systemd           
  tcp6       0      0 :::111                  :::*                    LISTEN      966/rpcbind         
  

• After reloading systemd, rpcbind listens on both tcp/111 and tcp6/111 ports while it should not (systemd is supposed to listen on these ports)

  # systemctl daemon-reload
  # netstat -anlp | grep -w -e 111 | grep LISTEN
  tcp        0      0 0.0.0.0:111             0.0.0.0:*               LISTEN      966/rpcbind         
  tcp6       0      0 :::111                  :::*                    LISTEN      966/rpcbind         
  

• Restarting the nfslock.service unit fails in error

  # systemctl restart nfslock.service
  A dependency job for rpc-statd.service failed. See 'journalctl -xe' for details.
  
  # systemctl status nfslock.service
  ● rpc-statd.service - NFS status monitor for NFSv2/3 locking.
         Loaded: loaded (/usr/lib/systemd/system/rpc-statd.service; static; vendor preset: disabled)
         Active: inactive (dead) since Fri 2018-03-02 13:01:10 CET; 17s ago
   Main PID: 966 (code=exited, status=0/SUCCESS)
  
  systemd[1]: Stopping NFS status monitor for NFSv2/3 locking....
  systemd[1]: Dependency failed for NFS status monitor for NFSv2/3 locking..
  systemd[1]: Job rpc-statd.service/start failed with result 'dependency'.