Displaying of the "Save as" dialog takes extremely long when downloading a large file

Symptoms

When downloading a large file from the Internet via F-Secure Internet Gatekeeper for Linux (FSIGK for Linux), it takes exceptionally long before the Save as dialog is displayed in the web browser.

Diagnosis

When you download a large file from the Internet via FSIGK for Linux, it takes extremely long - up to several minutes - before the Save as dialog is displayed in the web browser.

The reason for this is that the file is not actually downloaded by the client itself but by FSIGK for Linux. To be able to scan the file, it needs to be downloaded entirely into the scanning proxy. Once the file is downloaded, only then it is sent to the client using the web browser.

The browser, on the other hand, will show the Save as dialog only after having received a certain amount of bytes from the gatekeeper. Both Internet Explorer and Mozilla Firefox browsers need approximately 300 bytes before they can display the Save as dialog.

Solution

As this is actually not an issue, you can only inform the users by explaining to them how the Save as dialog works and why it can take some time before it is displayed when FSIGK for Linux is involved in the scanning.

Alternatively, you can enable data trickling in FSIGK for Linux. This simply means that FSIGK for Linux sends a specific number (YYY) of bytes every XXX seconds to the web browser. To do this:

  1. Open /opt/f-secure/fsigk/conf/fsigk.ini for editing.
  2. Add the following lines to the http section:
    [http]
    trickle=yes
    trickle_interval=30
    trickle_bytes=300

Warning: As the file is not yet scanned, this setting can allow malicious code through the FSIGK proxy.

Pricing & Product Info

For product info and pricing please go to the F-Secure product page

Version history
Revision #:
11 of 11
Last update:
Tuesday
Updated by:
 
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