NETGEAR FVS318 - ProSafe VPN Firewall Router Reference Manual page 126

Reference Manual for the Model FVS318 Broadband ProSafe VPN Firewall
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 255.255.255.0 into 16 subnets (4 bits), the new subnet mask becomes 255.255.255.240.
Table B-1. Netmask Notation Translation Table for One Octet
Number of Bits
1
2
3
4
5
6
7
8
The following table displays several common netmask values in both the dotted-decimal and the
mask length formats.
Table B-2. Netmask Formats
Dotted-Decimal
255.0.0.0
255.255.0.0
255.255.255.0
255.255.255.128
255.255.255.192
255.255.255.224
255.255.255.240
255.255.255.248
255.255.255.252
B-6
Dotted-Decimal Value
128
192
224
240
248
252
254
255
Masklength
/8
/16
/24
/25
/26
/27
/28
/29
/30
M-10146-01
Networks, Routing, and Firewall Basics