diff --git a/config/filter.d/vsftpd.conf b/config/filter.d/vsftpd.conf
index 59ce49a3..4de2befb 100644
--- a/config/filter.d/vsftpd.conf
+++ b/config/filter.d/vsftpd.conf
@@ -1,5 +1,8 @@
 # Fail2Ban filter for vsftp
 #
+# Configure VSFTP for "dual_log_enable=YES", and have fail2ban watch
+# /var/log/vsftpd.log instead of /var/log/secure. vsftpd.log file shows the
+# incoming ip address rather than domain names.
 
 [INCLUDES]
 
@@ -16,3 +19,4 @@ failregex = ^%(__prefix_line)s%(__pam_re)s\s+authentication failure; logname=\S*
 ignoreregex = 
 
 # Author: Cyril Jaquier
+# Documentation from fail2ban wiki