How to limit users who cannot use FTP in Linux
There is a file in / etc as an FTPUsers file, which is the user list that cannot be uploaded by the FTP service! The default is root, uucp, news. This is also set for the safety of the system!
If you want a user to upload it in the FTP, you can join this file directly to this file. Vioence, if you want it to be uploaded with FTP, you can delete it in this file!
Since the post is too short, add some network basics!
Division of subnet: Network Level: Subnet Mask 1-127 255.0.0.0 (Class A) 128-191 255.255.0.0 (Class B) 192 255.255.255.0 (Class C) Network Address: With machine's IP address The network mask is made by And operation! Broadcast address: With the user's network address and the online mask of the network mask to make OR operations! When the broadcast address, do ping operations for all subnets, causing broadcast storms!
