Our Technical Support specialist Vineesh Mohan already posted on What is Network CIDR and how to find it?

As per his post, by going through below link, it will provide Network CIDR

http://www.webdnstools.com/dnstools/my-ip-address

Here we can check the another method to find the Network CIDR

STEP 1 : Go to the below website to get the IP – http://flashwebhost.com/ip.php

STEP 2 : Open Terminal and add your IP like below

whois 10.0.0.0

STEP 3 : The above command will provide the first and last IP.

10.0.0.0 - 10.0.0.255

STEP 4 : Go to https://www.ipaddressguide.com/cidr and enter first and last IP and then click calculate button

I used the Network CIDR to secure wordpress using .htacess