User manual

SM User Manual January 2004
Software Release 4.1
6 IP NETWORK PLANNING
A proper IP addressing method is critical to the operation and security of a Canopy network. The
following information provides the background for the planner or operator to select an appropriate
method.
6.1 GENERAL IP ADDRESSING CONCEPTS
Basic concepts of IP addressing and subnet masks are required for networking.
6.1.1 IP Address
The IP address is a 32-bit binary number that has four parts (octets). This set of four octets has two
segments, depending on the class of IP address. The first segment identifies the network. The
second identifies the hosts or devices on the network. The subnet mask marks a boundary
between these two sub-addresses.
6.1.2 Subnet Mask
The subnet mask is a 32-bit binary number that filters the IP address. Where a subnet mask
contains a bit set to 1, the corresponding bit in the IP address is part of the network address.
6.1.3 Example IP Address and Subnet Mask
In Figure 28, the first 16 bits of the 32-bit IP address identify the network:
Octet 1 Octet 2 Octet 3 Octet 4
IP address 169.254.1.1
10101001 11111110 00000001 00000001
Subnet mask 255.255.0.0 11111111 11111111 00000000 00000000
Figure 28: Example of IP address in Class B subnet
In this example, the network address is 169.254, and 2
16
(65,536) hosts are addressable.
6.1.4 Subnet Classes
A subnet is classified as either a Class A, Class B, or Class C network. Subnet masks that classify
the network are shown in Table 10.
Table 10: Subnet masks for Network Classes A, B, and C
Class Network Portion Host Portion
A 11111111 00000000 00000000 00000000
B 11111111 11111111 00000000 00000000
C 11111111 11111111 11111111 00000000
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