ISA Server 2004 and FTP Access denied

by | May 11, 2006 | Blog, Computer Tips | 3 comments

denideWe’ve had Microsoft ISA Server running for a couple of weeks and ever since we upgraded to the new version we haven’t been able to write new files or delete existing files from an FTP connection.

The wierd thing is that we could make a FTP connection and download anything we wanted. We checked the permissions first because that’s what it really seemed like. However, we could make a FTP connection on a computer that wasn’t behind the ISA Server and delete to our heart’s content, so we knew it had to be something to do with the proxy server/firewall.

After some research on the web and some trial and error I finally figured it out. By default ISA Server 2004 restricts FTP traffic to read only. To change this you need to configure the FTP filter that allows the FTP traffic. For our setup the rule that allows the FTP traffic is called “Unrestricted Internet” rule, right-click and select Configure FTP. You’ll get the “Configures STP protocol policy” dialog bog and you’ll notice that the Read Only is checked. Remove the check box and hit ok. Then you’ll have to hit apply to save changes to the configuration.

After that make sure you disconnect your FTP session and reconnect since the new configuration has been applied. Once you re-connect you’ll be able to upload and delete all the files you want!

config

3 Comments

  1. Taylor
    Taylor on May 26, 2006 at 4:13 pm

    This is the most rediculous default behaviour I can imagine. I fought with wu-ftp on our OpenServer box for four hours because VPN clients were being 550’ed from deleting things when internal clients worked fine. The clincher in realizing it was ISA was when I finally got debugging turned on in wu-ftp, and discovered that the server wasn’t even receiving the DELE command. (At this point, I nearly cried.) A Google later, and your post showed up. This had all worked fine a few weeks ago, but we had migrated to ISA 2004 from 2000. Five minutes later, it was all working happily.

    Thanks! You saved me from mass murder or suicide!

  2. Gabriel
    Gabriel on June 1, 2006 at 8:49 am

    hi, that works just fine :) thanks a lot!!!

  3. Gilles Arlove
    Gilles Arlove on September 25, 2006 at 9:09 am

    Thanks ,

    I have been suffering with this restriction for a while did not even think it would be ISA causing , concentrated my efforts on the Web server I’ve been trying to upload to .

    thanks again worked perfectly all it took was one lousy right click !

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