Draytek Vigor3300 Series, User Manual

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Vigor3300 Series User’s Guide
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activities include no flag scan , FIN without ACK scan, SYN
FIN scan , Xmas scan and full Xmas scan .
Enable Tear Drop Activates the Block Tear Drop function. This attack involves
the perpetrator sending overlapping packets to the target hosts
so that target host will hang once they re-construct the packets.
The routers will block any packets resembling this attacking
activity.
Enable Ping of Death Activates the Block Ping of Death function. Many machines
may crash when receiving an ICMP datagram that exceeds the
maximum length. The router will block any fragmented ICMP
packets with a length greater than 1024 octets.
Enable Block ICMP
Fragment
Activates the Block ICMP fragment function. Any ICMP
packets with fragmented bit sets are dropped.
Enable Block Unknown
Protocol
Activates the Block Unknown Protocol function. The router
will block any packets with unknown protocol types.
Click Apply to apply the settings when you finish the configuration.
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The Internet contains a wide range of offenses or illegal materials. Unlike traditional media,
the Internet does not have any obvious tools to segregate materials based on URL strings or
content. URL content filtering systems are seen as tools that would provide the cyberspace
equivalent of the physical separations that are used to limit access to particular materials. By
rating a site as objectionable, and refusing to display it on user's browser, URL content filter
can prevent employee on SME from accessing inappropriate Internet resources.
Instead of traditional firewall inspects packets based on the fields of TCP/IP headers, the URL
content filter checks the URL strings or the payload of TCP/IP packets.
The URL content filter in the series of broadband security routers inspects every URL string in
the HTTP requestt. If the entire or part of the URL string (for instance,
http://www.draytek.com, as shown above) matches any activated rule, the first and the
following associate HTTP request will be blocked. The system will discard any request, which
tries to retrieve the malicious code.
Notice that you must clear your browser cache first so that the URL content filter operates
properly on a Web page that you visited before.