Are you using IE by chance? If yes, try accessing the FTP server using a different browser. IE has a known issue that such that it doesn't prompt end users to enter FTP server credentials when the user goes through any proxy (not just the WSA). We just decided to add this to the WSA release notes as a "known issue" with the different workarounds listed. You'll see it in the next version of the 7.5 release notes when that comes out someday. Here's what the bug write-up will say:
Defect ID 5463
Users cannot access FTP servers that require server authentication using FTP over HTTP with Internet Explorer. This is a known issue with Internet Explorer when communicating with web proxies. This is due to Internet Explorer never prompting users to enter the server authentication credentials. Workaround: To access FTP servers that require server authentication, use one of the following workarounds: Use a different browser, such as FireFox or Chrome, to access the FTP server. Use an FTP client that uses native FTP to access the FTP server. If users must use Internet Explorer, they can prepend the username and password into the URL. For example: ftp://USERNAME:PASSWORD@ftp.example.comPASSWORD@ftp.example.com
Table of ContentsIntroductionVersion HistoryPossible Future
UpdatesDocuments PurposeNAT Operation in ASA 8.3+ SectionsRule Types
Network Object NATTwice NAT / Manual NATRule Types used per SectionNAT
Types used with Twice NAT / Manual NAT and Network Obje...
Table of Contents Introduction:This document describes details on how
NAT-T works. Background: ESP encrypts all critical information,
encapsulating the entire inner TCP/UDP datagram within an ESP header.
ESP is an IP protocol in the same sense that TCP an...