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Reference Manual for the Model FVS318 Cable/DSL ProSafe VPN Firewall
B-2 Networks, Routing, and Firewall Basics
Routers vary in performance and scale, number of routing protocols supported, and types of
physical WAN connection they support. The Model FVS318 Cable/DSL ProSafe VPN Firewall is
a small office router that routes the IP protocol over a single-user broadband connection.
Routing Information Protocol
One of the protocols used by a router to build and maintain a picture of the network is the Routing
Information Protocol (RIP). Using RIP, routers periodically update one another and check for
changes to add to the routing table.
The FVS318 VPN Firewall supports both the older RIP-1 and the newer RIP-2 protocols. Among
other improvements, RIP-2 supports subnet and multicast protocols. RIP is not required for most
IP Addresses and the Internet
Because TCP/IP networks are interconnected across the world, every machine on the Internet must
have a unique address to make sure that transmitted data reaches the correct destination. Blocks of
addresses are assigned to organizations by the Internet Assigned Numbers Authority (IANA).
Individual users and small organizations may obtain their addresses either from the IANA or from
an Internet service provider (ISP). You can contact IANA at www.iana.org.
The Internet Protocol (IP) uses a 32-bit address structure. The address is usually written in dot
notation (also called dotted-decimal notation), in which each group of eight bits is written in
decimal form, separated by decimal points.
For example, the following binary address:
11000011 00100010 00001100 00000111
is normally written as:
The latter version is easier to remember and easier to enter into your computer.
In addition, the 32 bits of the address are subdivided into two parts. The first part of the address
identifies the network, and the second part identifies the host node or station on the network. The
dividing point may vary depending on the address range and the application.