Thank you very much Buchan.
<div>There was some problem with /etc/nsswitch.conf &nbsp;file.</div><div>I changed this configuration using "<span class="Apple-style-span" style="font-family: verdana, geneva, lucida, 'lucida grande', arial, helvetica, sans-serif, sans; font-size: 11px; background-color: rgb(250, 250, 250); ">env LANG=C authconfig-tui" command and selected LDAP option.&nbsp;</span></div><div><span class="Apple-style-span" style="font-family: verdana, geneva, lucida, 'lucida grande', arial, helvetica, sans-serif, sans; font-size: 11px; background-color: rgb(250, 250, 250); ">This will change the nsswitch.conf file properly.</span></div><div><span class="Apple-style-span" style="font-family: verdana, geneva, lucida, 'lucida grande', arial, helvetica, sans-serif, sans; font-size: 11px; background-color: rgb(250, 250, 250); "><br></span></div><div><span class="Apple-style-span" style="font-family: verdana, geneva, lucida, 'lucida grande', arial, helvetica, sans-serif, sans; font-size: 11px; background-color: rgb(250, 250, 250); ">Thank you.</span></div><br><A HREF="http://sigads.rediff.com/RealMedia/ads/click_nx.ads/www.rediffmail.com/signatureline.htm@Middle?" target="_blank"><IMG SRC="http://sigads.rediff.com/RealMedia/ads/adstream_nx.ads/www.rediffmail.com/signatureline.htm@Middle"></A><br>Treat yourself at a restaurant, spa, resort and much more with <b><a href="http://track.rediff.com/click?url=___http://dealhojaye.rediff.com?sc_cid=mailsignature___&cmp=signature&lnk=rediffmailsignature&newservice=deals" target ="_new">Rediff Deal ho jaye!</a></b>