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Unable to Download from FTP:// Sites - 22.May2003 11:38:00 AM

rfullford

Posts: 16
Joined: 31.Jan.2003
From: ACT, Australia
Status: offline

We have set up an ISA Server to assess GFi DownloadSecurity. The server is set up with firewall and caching but has a single NIC.

When we attempt to download a file where the link is to an ftp://ftp.domain.com/... we get an error from the ISA Server as follows:

ISA Server: extended error message :
200 Type set to I
425 Cannot establish data connection

If we manually set the link to the form http://ftp.domain.com/... The download works correctly.

Any suggestions?

Post #: 1

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RE: Unable to Download from FTP:// Sites - 5.Jun.2003 4:40:00 AM

tshinder

Posts: 47659
Joined: 10.Jan.2001
From: Texas
Status: offline

Hi R,

Are the clients configured as Web Proxy clients?

Thanks!
Tom

(in reply to rfullford)

Post #: 2

RE: Unable to Download from FTP:// Sites - 12.Jun.2003 8:04:00 AM

rfullford

Posts: 16
Joined: 31.Jan.2003
From: ACT, Australia
Status: offline

Thanks for reply. Hadn't visited in a few days and the e-mail notification didn't work? Anyway ... yes, they are configured as Web Proxy clients. Have done some more troubleshooting on this. There is an external firewall that seems to block ftp:// type downloads unless they come through another proxy set up at the boundary of our network. So we have ISA -> Other Proxy -> External Firewall as the required path. Is it possible to get ISA to run all the http:// and ftp:// through this other proxy? It is not an ISA server and only identifiable by IP address.

(in reply to rfullford)

Post #: 3

RE: Unable to Download from FTP:// Sites - 13.Jun.2003 8:49:00 PM

tshinder

Posts: 47659
Joined: 10.Jan.2001
From: Texas
Status: offline

Hi R,

You can route Web Proxy client requests to an upstream, but the ISA firewall will forward it as an FTP request instead of HTTP.

HTH,
Tom

(in reply to rfullford)

Post #: 4

RE: Unable to Download from FTP:// Sites - 14.Jun.2003 3:28:00 AM

rfullford

Posts: 16
Joined: 31.Jan.2003
From: ACT, Australia
Status: offline

That's OK. The upstream does allow the FTP requests. I've tested by pointing IE directly at the upstream proxy and FTP downloads work.

Where to I set up ISA to route we proxy requests to the upstream server?

(in reply to rfullford)

Post #: 5

RE: Unable to Download from FTP:// Sites - 14.Jun.2003 12:02:00 PM

spouseele

Posts: 12782
Joined: 1.Jun.2001
From: Belgium
Status: offline

Hi rfullford,

you should test with the standard Microsoft command line FTP client to be really sure the upstream proxy supports FTP requests. To learn more about how IE handles FTP requests, check out my article http://www.isaserver.org/articles/How_the_FTP_protocol_Challenges_Firewall_Security.html, especially section '4.4. Web Proxy client'.

HTH,
Stefaan

(in reply to rfullford)

Post #: 6