The firewall is the mode of two-node cluster aware ,some external network users cannot download files when they interview internal network FTP.
1、 Connect FTP and use the order of dir to display files ,it will register information as follows :
550 Permission denied.
Passive mode refused. Turning off passive mode.
This mistake will be appeared when the FTP server configure nonsupport connection of passive mode.
2、 Changing to the active mode at the client ,testing again and the information as follows：425 Failed to establish connection.
3、 Ensure the server uses the active mode with client.Check the session list ,it can found the session of ftp data the two situation above .It can explain that the firewall dones’n forbid the session
4、 Changing to passive mode at the FTP server and testing FTP normal ,there is no problem in uploading and downloading data.
The reason to this problem is the difference of transmission mode between client and server ,and both exports have the firewall.
IE browser is one of the most simple and direct tool which has been used to enter FTP server ,the default mode is active and the way to switch is very simple.After startup IE ,we open ”Internet option”in the menu of “tool” ,and switch to “high” option card and choose “using passive FTP” option and save the setting .