How to do it...

1. To scan for FTP servers on the network, use the auxiliary/scanner/ftp/ftp_version auxiliary module, set the target address range in RHOSTS, and the number of concurrent threads to 256:

msf > use auxiliary/scanner/ftp/ftp_version 
msf auxiliary(ftp_version) > set RHOSTS 192.168.216.10,129
RHOSTS => 192.168.216.10,129
msf auxiliary(ftp_version) > set THREADS 256
THREADS => 256
msf auxiliary(ftp_version) > run

[+] 192.168.216.129:21 - FTP Banner: '220 (vsFTPd 2.3.4)\x0d\x0a'
[*] Scanned 1 of 2 hosts (50% complete)
[*] Scanned 2 of 2 hosts (100% complete)
[*] Auxiliary module execution completed
msf auxiliary(ftp_version) > 

1. The scan results, as with the previous auxiliary modules, will get stored in the Metasploit database and can be accessed using the services command:

msf auxiliary(ftp_version) > services 

Services
========

host port proto name state info
---- ---- ----- ---- ----- ----
192.168.216.129 21 tcp ftp open 220 (vsFTPd 2.3.4)\x0d\x0a

msf auxiliary(ftp_version) >