When downloading files, status page keeps reappearing or giving a 555 internal server error at the end


This article applies to:

  • SWG 9.x , 10.x , 11.x

Symptoms:

  • When downloading files the download page keeps reappearing or giving a 555 internal server error at the end

Causes:

With the limited shell command config_network, check if the scanners have an interface with the IP they have in the GUI->Devices.
The problem may lie with the fact that the scanners don't have an interfacewith the IP that you see in the GUI and a load balancer is used. The scanners assume they canconnect to each other with the IP seen in the GUI.

The download with status page flow goes like this:
  • Client requests file, via LB, from scanner A ->scanner A starts the download and sends the status page to the client -> When download/scan is complete the scanner sends a redirect response to the client with a url pointing to the file location on the scanner and parameter with the scanner ip. -> client follows the redirect url and the LB directs it this time to scanner B -> scanner B checks if the scanner IP address in the request parameter is his IP address.
    • If it is his IP address (A==B) , it returns the scanned file to the client
    • If its not his IP address, it connects to that IP address (scanner A which holds the downloaded file) and streams the file back to the client.
In our test B was not A so it tried to connect to A and failed. Thiscaused the 555 - internal server error response, that was sent to theclient.

Resolution:

Two options:

  1. Use a free network interface on each scanner to assign it the IP that we see in the GUI, in a way they can connect to each other. e.g. As a VLAN that only the scanners can see.
  2. Disable the status page feature.

Last Modified 8/9/2012.
https://support.trustwave.com/kb/KnowledgebaseArticle14910.aspx