Why is Pattern showing up in the probes and reports?


This article applies to:

  • R3000/WF/WFR

Question:

Why is Pattern showing up in the probes and reports?

Reply

Why is Pattern showing up in the probes and reports?
By design, the pattern-based filtering is identifying traffic on the signature of the request rather than identifying a known-destination. Because this is extremely processing intensive, we simply identify the traffic when it matches a particular signature and log the destination IP address of that traffic.

What you may see in probes
PROXY,1,7,,pattern://72.165.141.81/, pattern://72.165.141.81/   where 1= blocked and 7=block method, pattern in this case
or
PATTERN//157.233.101.99/  These pattern ip typically do not go to a website, since it is a signature pattern not a domain.  
The filter Software version 4.x or higher has this new pattern filtering Whitelist: the new Pattern Detection Whitelist window (Library > Pattern Detection Whitelist) lets you create a list of IP addresses that will always bypass pattern detection filtering. If the above ip is a server, it must be excluded from the range to detect section.
Another option is to exclude a source ip address in the Global Group > Range To Detect section. If you have multiple range to detect settings, select the source ip that needs access to this site then add the excluded ip address in step 4 of the wizard.

Using an internal Proxy
When looking at traffic that is going through a proxy server, the destination IP address is in fact the proxy server, so by design, the filter will log that instead of the real site outside the network. We do not maintain a state table of which connection (from client to proxy server) is going to which destination (from proxy server to internet destination), due to the processing overhead associated with the signature matching as it is.


This article was previously published as:
8e6 KB 300017

Last Modified 4/17/2012.
https://support.trustwave.com/kb/KnowledgebaseArticle12610.aspx