su not giving proper message for restricted LDAP groups

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http://serverfault.com – I have configured PAM authentication on Linux box to restrict particular group only to login. I have enabled pam and ldap through authconfig and modified access.conf like below, [root@test root]# tail -1 /etc/security/access.conf - : ALL EXCEPT root test-auth : ALL Also modified sudoers file, to get su for this group <code> [root@test ~]# tail -1 /etc/sudoers %test-auth ALL=/bin/su</code> Now, only this ldap group members can login to system. However when from any of this authorized user, I tried for su, it asks for password and then though I enter correct pas (HowTos)