Netgear FVS318v3 사용자 설명서

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Reference Manual for the ProSafe VPN Firewall FVS318v3
Network, Routing, and Firewall Basics
B-7
January 2005
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 FVS318v3 VPN 
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.
255.255.0.0
/16
255.255.255.0
/24
255.255.255.128
/25
255.255.255.192
/26
255.255.255.224
/27
255.255.255.240
/28
255.255.255.248
/29
255.255.255.252
/30
255.255.255.254
/31
255.255.255.255
/32
Table B-2.
Netmask formats