How to create a Password Protected Directory using linux command prompt?

Create a .htaccess file in the folder you want to set.
like:
#root@adu [/home/hostsite/public_html/admin]# vi .htaccess
copy and paste the following lines:
———————————————————-
AuthName “Secure Area”
AuthType Basic
AuthUserFile /home/hostsite/public_html/admin/.htpasswd
require valid-user
———————————————————-
Now set a password:
#htpasswd -c .htpasswd admin
New password: admin321
confirm password: admin321

You are done. test it: http://www.hostsite.com.au/admin and enter user name as admin and password as admin321

Unblocking IP address in Cpanel Server or Linux Command Line

You can unblock if from server shell console or from csf plugin if the serve is running cpanel.

For 125.214.71.115 in WHM under the Plugins section go to ConfigServer Security&Firewall.
Quick Allow tool should solve any blocking issues.

If the server is not running Cpane then from linux console run :
csf -a $IP
where $IP is IP you want to unblock and whitelist.

e.g:

root@secure [~]# csf -a 110.174.81.206
Removing 110.174.81.206 from csf.deny and iptables DROP…
DROP  all opt — in !lo out *  110.174.81.206  -> 0.0.0.0/0
DROP  all opt — in * out !lo  0.0.0.0/0  -> 110.174.81.206
Adding 110.174.81.206 to csf.allow and iptables ACCEPT…
ACCEPT  all opt — in !lo out *  110.174.81.206  -> 0.0.0.0/0
ACCEPT  all opt — in * out !lo  0.0.0.0/0  -> 110.174.81.206
root@secure [~]#