VSFTPD limit the number of simultaneous vsftpd connections for a single IP address

To limit the number of simultaneous FTP connections for a single IP address in vsftpd, you can use the max_per_ip option in the vsftpd configuration file (/etc/vsftpd.conf).

To set the maximum number of connections to 2 for a single IP address, add the following line to the configuration file:

max_per_ip=2

Then, restart vsftpd to apply the changes:

sudo service vsftpd restart

Note that this option will apply to all IP addresses connecting to the FTP server. If you want to set different maximums for different IP addresses, you can use the max_per_ip option in a user configuration file in the /etc/vsftpd/user_list directory.

For example, to set the maximum number of connections to 3 for the IP address 192.168.1.100, create a file named 192.168.1.100 in the /etc/vsftpd/user_list directory with the following contents:

max_per_ip=3