'pasv_min_port' and 'pasv_max_port' directives of vsftpd not working to limit the port ranges

Issue

• vsftpd 'pasv_min_port' and 'pasv_max_port' not working to limit the port range
• Below port ranges are configured on vsftpd server, but the ftp connection uses a port not in the specified range.

/etc/vsftpd.conf:
pasv_min_port=10000
pasv_max_port=20000

• netstat output shows the connection from 55776 port, which is not in the range.

tcp        0      0 0.0.0.0:21                  0.0.0.0:*                   LISTEN
tcp        0      0 192.4.53.228:21             128.96.130.76:55776         ESTABLISHED