Private Ip Addresses - NETGEAR FR328S Cable/DSL ProSafe Firewall FR328S FR328S Reference Manual

Table 8-2. Netmask Formats
255.255.255.252
255.255.255.254
255.255.255.255
Configure all hosts on a LAN segment to use the same netmask for the following reasons:
• So that hosts recognize local IP broadcast packets
When a device broadcasts to its segment neighbors, it uses a destination address of the local
network address with all ones for the host address. In order for this scheme to work, all devices
on the segment must agree on which bits comprise the host address.
• So that a local router or bridge recognizes which addresses are local and which are remote

Private IP Addresses

If your local network is isolated from the Internet (for example, when using NAT), you can assign
any IP addresses to the hosts without problems. However, the IANA has reserved the following
three blocks of IP addresses specifically for private networks:
10.0.0.0 - 10.255.255.255
172.16.0.0 - 172.31.255.255
192.168.0.0 - 192.168.255.255
Choose your private network number from this range. The DHCP server of the FR328S Firewall
is preconfigured to automatically assign private addresses.
Regardless of your particular situation, do not create an arbitrary IP address; always follow the
guidelines explained here. For more information about address assignment, refer to RFC 1597,
Address Allocation for Private Internets, and RFC 1466, Guidelines for Management of IP
Address Space. The Internet Engineering Task Force (IETF) publishes RFCs on its Web site at
www.ietf.org.
Networks, Routing, and Firewall Basics
FR328S ProSafe Firewall with Dial Back-Up Reference Manual v2
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M-10207-01, Reference Manual v2
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