If you want to disable detection of OS version during Nmap scans

1. Edit the sysctl.conf file


vi /etc/sysctl.conf


2. Add the following entry at the end of the file


net.ipv4.ip_default_ttl = 199


save and exist.


3. Run the following command to reload the sysctl configuration


/sbin/sysctl -p


4. You can now check the result by running an online nmap test here