Which of the following is specifically filtered by a URL filtering subscription service on a Cisco router? (Select
the best answer.)
A.
traffic sent from specific domains
B.
traffic that contains specific keywords
C.
traffic that contains malicious software
D.
traffic that matches predefined categories
Explanation:
On a Cisco router, traffic that matches predefined categories is filtered by a Uniform Resource Locator
(URL) filtering subscription service. URL filtering inspects Hypertext Transfer Protocol (HTTP) requests and
blocks access to websites that match certain criteria. Subscriptionbased URL filtering services, which are
offered by Trend Micro, Websense, and Secure Computing, assign websites to categories, which are used by
administrators to limit or block access to these sites. URL filtering is commonly configured on perimeter routers
to prevent users from inadvertently accessing URLs that have been deemed inappropriate or identified as
containing malware.Although a URL filtering subscription service does not specifically filter traffic that contains malicious software
as a payload, you can configure the local URL filtering service so that access to websites known to distribute
malicious software is filtered. For example, if a particular URL is known to harbor malware, you could filter that
specific URL or the entire domain. However, to filter traffic that contains malicious software as a payload, you
should install an Intrusion Prevention System (IPS).Cisco: Subscriptionbased Cisco IOS Content Filtering
Cisco: Cisco IOS Content Filtering Configuration Guide