When you use WCCP for FTP traffic through IWSVA, Passive FTP does not work. The packet capture shows the following information when accessing an FTP site:
2011/11/15 13:59:09 GMT-08:00 <2324> [266] HandleIO returned NEED_MORE_DATA
2011/11/15 14:00:39 GMT-08:00 <2324> select() timeout
2011/11/15 14:00:39 GMT-08:00 <2324> Discard socket [8] at index 0
2011/11/15 14:00:39 GMT-08:00 <2324> Discard socket [265] at index 1
2011/11/15 14:00:39 GMT-08:00 <2324> Discard socket [266] at index 3
2011/11/15 14:00:39 GMT-08:00 <2324> Discard socket [267] at index 4
2011/11/15 14:00:39 GMT-08:00 <2324> [8] Closing Connection
2011/11/15 14:00:39 GMT-08:00 <2324> TmIscanBaseServer::DoDeferredProcessing(), size:0
The issue occurs because WCCP does not support Passive FTP, where a random data port is defined during connection. The WCCP device does not forward this data port to IWSVA, causing the connection to fail.
To resolve the issue, configure the browser to use Active FTP:
- For Internet Explorer: Go to Internet Options > Advanced and deselect the Use Passive FTP option.
- For Google Chrome: On the Internet Properties window, click Advanced tab and deselect the Use Passive FTP option.
- For Safari:
- Version 10.2:
- Go to System Preferences > Network > Proxies.
- Disable Use Passive FTP Mode.
- Version 10.3 or higher:
- Go to System Preferences > Network and then double-click the green bulleted item.
- Go to Proxies and disable Use Passive FTP Mode.
- Version 10.2:
