The NIS server and client are deployed on the same computer, and yp_all: clnt_call: RPC: Time is displayed.

The NIS server and client are run on the same computer. The yp_all: clnt_call: RPC: Time -- Linux Enterprise Application-Linux server application information is displayed. For details, see the following. Now that the server and client have been set up, I have re-created the stored files for NIS users, modified the query address of makefile, set up the database, and re-enabled the service, during User Switching, the above error message will appear in about 30 seconds, but the user switches to the user who wants to switch. When I switch from the root user to the NIS user, in order to determine whether the switchover is successful or not, the read and write operations on some documents are indeed insufficient, indicating that the user has switched, however, there are still error messages and waiting time. When the nis service is enabled, the same problem occurs during the Local User Switching process. However, after the nis client is closed, the Local User Switching is normal. I am wondering what the problem is.