
Appendix B IP Addresses and Subnetting
FSG1100HN User’s Guide
116
Subnet Mask - Identifying Network Number
OCTET:
OCTET:
OCTET:
OCTET:
By convention, subnet masks always consist of a continuous sequence of ones
beginning from the leftmost bit of the mask, followed by a continuous sequence
of zeros, for a total number of 32 bits.
Subnet masks can be referred to by the size of the network number part (the bits
with a “1” value). For example, an “8-bit mask” means that the first 8 bits of the
mask are ones and the remaining 24 bits are zeroes.
Subnet masks are expressed in dotted decimal notation just like IP addresses.
The following examples show the binary and decimal notation for 8-bit, 16-bit,
24-bit and 29-bit subnet masks.
Subnet Masks
DECIMAL
mask
Network Size
The size of the network number determines the maximum number of possible
hosts you can have on your network. The larger the number of network number
bits, the smaller the number of remaining host ID bits.
An IP address with host IDs of all zeros is the IP address of the network
(192.168.1.0 with a 24-bit subnet mask, for example). An IP address with host
IDs of all ones is the broadcast address for that network (192.168.1.255 with a
24-bit subnet mask, for example).
Comentarios a estos manuales