NETGEAR ProSafe FWAG114, Справочное руководство, Страница: 122 / 192

Reference Manual for the ProSafe Dual Band Wireless VPN Firewall FWAG114
B-2 Network, Routing, Firewall, and Basics
What is a Router?
A router is a device that forwards traffic between networks based on network layer information in
the data and on routing tables maintained by the router. In these routing tables, a router builds up a
logical picture of the overall network by gathering and exchanging information with other routers
in the network. Using this information, the router chooses the best path for forwarding network
traffic.
Routers vary in performance and scale, number of routing protocols supported, and types of
physical WAN connection they support. The ProSafe Dual Band Wireless VPN Firewall
FWAG114 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 FWAG114 wireless 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 home applications.
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: