One client has problems, but other clients on the same subnet are operating normally. On the problem client, run ls -l on a directory, such as /usr, that contains files owned by many users, including some not in the client /etc/passwd file. If the resulting display lists file owners who are not in the local /etc/passwd as numbers, rather than names, this indicates that NIS service is not working on the client.
These symptoms usually mean that the client ypbind process is not running. Run ps -e and check for ypbind. If you do not find it, log in as superuser and start ypbind by typing: