User`s guide
VigorPro5510 Series User’s Guide
64
the IP Alias List, the Public IP setting will be empty in this field.
When you click Apply, a message will appear to inform you.
Private IP Assign an IP address (e.g., 192.168.1.10) or a subnet to be
compared with the Public IP address for incoming packets.
Subnet Mask Select a value of subnet mask for private IP address.
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While the broadband users demand more bandwidth for multimedia, interactive applications,
or distance learning, security has been always the most concerned. The firewall of the Vigor
router helps to protect your local network against attack from unauthorized outsiders. It also
restricts users in the local network from accessing the Internet. Furthermore, it can filter out
specific packets that trigger the router to build an unwanted outgoing connection.
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The users on the LAN are provided with secured protection by the following firewall
facilities:
z User-configurable IP filter (Call Filter/ Data Filter).
z Stateful Packet Inspection (SPI): tracks packets and denies unsolicited incoming data
z Selectable Denial of Service (DoS) /Distributed DoS (DDoS) attacks protection
z URL Content Filter
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Depending on whether there is an existing Internet connection, or in other words “the WAN
link status is up or down”, the IP filter architecture categorizes traffic into two: Call Filter
and Data Filter.
z Call Filter - When there is no existing Internet connection, Call Filter is applied to all
traffic, all of which should be outgoing. It will check packets according to the filter
rules. If legal, the packet will pass. Then the router shall “initiate a call” to build the
Internet connection and send the packet to Internet.
z Data Filter - When there is an existing Internet connection, Data Filter is applied to
incoming and outgoing traffic. It will check packets according to the filter rules. If legal,
the packet will pass the router.
The following illustrations are flow charts explaining how router will treat incoming traffic
and outgoing traffic respectively.