IIS: FTP Users Will Still Be Prompted for Credentials Even From a Restricted IP Address

• Microsoft Internet Information Server versions 3.0, 4.0, 5.0

SYMPTOMS

When users connect to an IIS FTP server from a restricted IP address, they will still be prompted for credentials.
For example, you have an FTP site at 192.168.1.1 with IP Address and Domain Restrictions, by default, set to denied access. If a user from a denied IP connects to your FTP server, he will be prompted for credentials. Once the user logs into the server, he will receive an access denied message from the server.

CAUSE

Once an FTP connection is established, a client/server handshake must take place before anything else can be done. Part of this handshake is obtaining the username and password to be used for the connection. Once the necessary handshake is finished, then the IP restrictions are checked.

Keywords :
Version : winnt:3.0,4.0,5.0
Platform : winnt
Issue type :