Configuring the WSA and the ASA for FTP can be a little tricky.
Log into the WSA
Security Service à FTP Proxy
Enable FTP Proxy
Assign Port to listen on – Default is 21
Enable Caching
Choose authentication option
The remaining defaults are preferred
Network à Transparent Redirection à Add Services
Add desired name – WCCP_FTP_21
Enter number for Dynamic Service ID – 95
Enter the Following Port Numbers – 11000,11001,11002,11003,11004,11005,11006,11007
Choose Redirection option
Choose load balancing options.
Enter Router IP Address – Internet access route (default route)
Enable and Enter Password if desired
Submit and commit changes.
Repeat exact process for the FTP Port 20 – with the exception of the server name and Dynamic Service ID.
Save and commit changes.