How do you whitelist IPs for the service to allow only certain subnets on? Do I use IPTables or is there an easier way like IPWrappers Do you have to register the service for it to work with IPWrappers(hosts.allow)
If your vsftpd has been compiled with tcp_wrappers support then you can use it if you turn on the vsftpd configurstion option
You can check to see if your vsftpd has been compiled with libwrap support like so
The easiest way would be to use iptables:
to allow from 18.104.22.168/24 and 22.214.171.124/24 and dissallow from everyone else.
Don't forget to save iptables configuration (depends on your linux distro), so it will survive reboot.