Accessing FTP sites using Internet Explorer

[munrobasher]

I asked a brief question about this recently but didn't get very far but I need to re-visit as the requirement to use FTP is increasing.

Internet Explorer 6 is configured to proxy via VSERVER01 for all protocols. WinGate is running on VSERVER01 with no authentication, i.e. everyone has internet access.

Works a treat for HTTP traffic but we just can't get FTP fully working.

Problem #1 - access an FTP site that doesn't require a password (like ftp.microsoft.com) with "Enable folder view for FTP" turn on and you "Windows cannot access this folder. Make sure you typed the file name correctly and that you have permission to access the folder. Details: The operation timed out". It works okay when folder view is disabled so that could be a workaround for us (we could modify the logon script to disable this feature or use a policy).

Problem #2 - even with folder view turned off, we can't access FTP sites that require a username and password. It either times out or says "Your are not authorised to view this page".

The command line FTP.EXE works fine if we logon using the user@site format of authentication but the command line tool is not suitable for our users.

CuteFTP works okay as you can configure it to use user@site authentication but that is a bit of an overkill for us.

Help!

Thanks, Rob.

[adrien]

hi Rob

FTP through HTTP has always been a bit of a pig. In fact I think the whole concept is right up there in the poorly thought out design stakes.

Problem is that the browser no longer talks FTP protocol. It talks HTTP to the proxy, and the proxy then has to talk FTP to the FTP server, then translate the content back to something that the browser will swallow given that it's expecting an HTTP response. So for Wingate, we have to generate HTML of directory listings etc etc etc, we have to download files, try and figure out a mime type etc etc. It's really hideous.

In general we've found the best way to get FTP working (even with a direct connection IE is still a pig of an FTP client - hangs all over the place) is by avoiding using the HTTP proxy for FTP. The easiest solution for this is to configure only 1 entry in the proxy settings for IE.

Http: WinGate:80

and use NAT for everything else. If you aren't able to use NAT for whatever reason, a fall-back is to use SOCKS, in which case you'd add

SOCKS: WinGate:1080

Then IE will use SOCKS for all connectivity other than HTTP. This covers things like java applets as well.

I believe that FTP in IE uses PASV mode as well, so you should see 2 connections going out through SOCKS. You do need to disable connection interception in the FTP proxy though, otherwise it makes a mess of the FTP over SOCKS data connections.

I'll also take another look in the lab and see if we can repro this issue.

Adrien