Dear Rowland. Your tip has been very satisfactory. The symbolic link commands to libnss_winbind I just ran on DC2.I forgot to run the following commands in the DC1: # ln -s /usr/local/samba/lib/libnss_winbind.so.2 /lib64/ # ln -s /lib64/libnss_winbind.so.2 /lib64/libnss_winbind.so Thanks for the support.