Materials Analysis Research Laboratory - Accessing files through FTP

General

MARL makes practically all results available over the web via an FTP server. Therefore, results may be accessed as soon as the files are stored. Either web browsers or ftp clients may be used to access and retrieve the data.

Most files are stored in directories that can be accessed using anonymous ftp ( i.e., no login is required). Sensitive files are stored in a separate area and are protected by a password. Please contact MARL staff if privacy is an issue and such a directory will be set up.

Results from the scanning electron microscopes (SEMs), the X-ray fluorescence (XRF) spectrometer, the X-ray diffractometer (XRD), and the light microscopes are available at ftp://www.marl.iastate.edu. Results from the thermal analyzers are available at ftp://ta.marl.iastate.edu.

Logging in

FTP clients generally prompt for username and password as part of establishing a connection to a server. Web browsers generally do not. Therefore, a special form of the web address is required to include the username and password. For our main site, the URL becomes ftp://user:password@www.marl.iastate.edu, where user and password are replaced with the appropriate names.

Alternatively, a user may navigate to our public ftp area as an anonymous user and then choose the File, LoginAs

Problems Accessing Files

We occasionally get reports of persistent difficulties in accessing files on our server. The problem usually manifests itself in not even being able to display a list of files on our servers. In all cases so far, this has proved to be do to problems on the client end rather than with our servers. Our servers are fairly basic in their configuration and require no special configuration on the client end.

However, many organizations are installing firewalls to either limit external access to their company networks, or to limit employee access to materials not related to work. These firewalls have proved to be the source of the problem in all cases to date.

Solution

The solution appears to be setting the client computer to employ "passive" ftp rather than normal ftp to access files on the MARL servers. Microsoft plainly states that the passive mode needs to be set to work with some firewalls and routers. Sometimes the IT department can make and will be willing to make a change to the firewall setting to allow access to our site. Usually, there is a setting within the program to set the mode. And still other times, a separate program such as SocksCap may be employed to work through the blockage at the firewall.

The procedure to set the passive mode varies depending on the web browser and its version. For Internet Explorer, navigate to the advanced tab under Internet options (Tools, Internet Options or Control Panel, Internet Options). Under the Brower section, one of the last options is to "Use passive FTP for compatibility with some firewalls and DSL modems" (Picture of settings window). Check the box, and click OK to save the settings.