NIS Password

Greetings All,

I am newbie to Unix. Have the following issue:
Users are unable to change their password themselves.
After they ash to a specific box (NIS Account is extended to that box)and then su as them with an assigned password and run command to change the password they get this error:

passwd -r nis username

Enter existing login password:

New Password:

Re-enter new Password:

Permission denied

Also tried to use passwd command and yppasswd
I do not have a problem changing their passwords via /etc/shadow file
Any help appreciated
Thanks

Make sure rpc.yppasswdd is running on your nis master server.
Further hints: Solaris NIS configuration

1) use "yppasswd" or "nispasswd" (both behaved the same as "passwd")
2) make sure rpc.yppasswdd is running (it was)
3) make sure ypserv is running (it was)
4) make sure permissions are correct on relevant directories/files (they were)
5) references to assorted patches that either fixed or caused an identical
problem
6) rebuild the maps

run with the correct -D option on
rpc.yppasswd, the problem was solved