A subnetwork or subnet is a logical subdivision of an IP network . The practice of dividing a network into two or more networks is called subnetting .
- Devices in the same subnet share the same network number or routing prefix
- In technical terms this is known as the most significant bit -group in their IP Addresses
- In layman terms this can also be considered the network ID
- The the second field (suffix) is considered the rest field or host identifier
- The routing prefix may be experessed in
Classless Inter-Domain Routing
(CIDR)
+ Example:
198.51.100.0/24or2001:db8::/32 - For
IPv4
a network may be characterized by
its subnet mask or netmask:
- This is the
bitmask
that when
applied by a
bitwise AND
operation to any IP address in the network, yields the routing prefix.
- Usually expressed in
dot-decimal notation
.
For example:
255.255.255.0is the subnet mask for the prefix198.51.100.0/24
- Usually expressed in
dot-decimal notation
.
For example:
- This is the
bitmask
that when
applied by a
bitwise AND
operation to any IP address in the network, yields the routing prefix.
Network addressing and routing #
STUB
IPv4 #
Determining the network prefix #
See Subnet Mask
Subnetting #
See Subnetting