Regularly check for and apply patches to your FTP server software. This includes not just the FTP server itself but also the operating system and any other software running on the server.
Are you experiencing any specific or login errors since the 10.16.100.244 server update? 10161oo244 icc ftp server patched
If any of these are true, treat the system as compromised and prioritize the immediately. Regularly check for and apply patches to your