NETGEAR FVS318 Router User Manual

Reference Manual for the Model FVS318 Cable/DSL ProSafe VPN Firewall
B-6 Networks, Routing, and Firewall Basics
The following table lists the additional subnet mask bits in dotted-decimal notation. To use the
table, write down the original class netmask and replace the 0 value octets with the dotted-decimal
value of the additional subnet bits. For example, to partition your Class C network with subnet
mask into 16 subnets (4 bits), the new subnet mask becomes
The following table displays several common netmask values in both the dotted-decimal and the
masklength formats.
Note: The number is not assigned because it is the broadcast address
of the first subnet. The number is not assigned because it is the network
address of the second subnet.
Table B-1. Netmask Notation Translation Table for One Octet
Number of Bits Dotted-Decimal Value
1 128
2 192
3 224
4 240
5 248
6 252
7 254
8 255
Table B-2. Netmask Formats
Dotted-Decimal Masklength /8 /16 /24 /25 /26 /27 /28 /29