The ypserv package can be removed with the following command:
$ apt-get remove ypserv
The NIS service provides an unencrypted authentication service which does not provide for the confidentiality and integrity of user passwords or the remote session. Removing the ypserv package decreases the risk of the accidental (or intentional) activation of NIS or NIS+ services.
The ypserv service, which allows the system to act as a client in
a NIS or NIS+ domain, should be disabled.
The ypserv service can be disabled with the following command:
$ sudo systemctl mask --now ypserv.service
Disabling the ypserv service ensures the system is not acting as a client in a NIS or NIS+ domain. This service should be disabled unless in use.