MICROSOFT BEGAN LISTING IP ADDRESS RANGES IN THE SAME MANNER THA...

2000, Microsoft began listing IP address ranges in the same manner that Ciscodoes. This method, Classless Interdomain Routing (CIDR), lists the IP address fol-lowed by the number of ones in the subnet mask. For instance, 192.168.1.0 with asubnet of 255.255.255.0 is written as 192.168.1.0/24. As a quick review, IP addresses are currently made up of 32 bits of information.Thesebits are divided into four sections (octets) that each contains 1 byte (6 bits).You will see IPaddresses specified in three basic formats:

■

Binary such as in 11000000.10101000.00000000.00000001

■

Dotted-decimal such as in 192.168.0.1

■

Hexadecimal such as in C0 A8 00 01All three of these examples represent the same IP address. In reality, the computer canuse only the binary version.The other two formats are provided because they are easier forpeople to understand and use.There are three basic types of IP addresses:

■

Unicast addresses IP addresses assigned to a single network interface that isattached on the network. Unicast IP addresses are used for one-to-one communi-cations between hosts.

■

Broadcast addresses IP addresses designed to be received and processed byevery IP address located on a given network.They’re basically one-to-many com-munications.

■

Multicast addresses IP addresses where one or more IP nodes can listen in onthe same network segment. Multicast IP addresses are also one-to-many commu-nications.Next, you should also understand the differences between routed and Network AddressTranslation (NAT) connections. NAT is the process of switching back and forth betweenthe IP addresses used on an internal network, sometimes referred to as private addresses, andInternet IP addresses, sometimes known as public addresses.There are three address blocks set aside and defined as private address space:

■

10.0.0.0 with a subnet mask of 255.0.0.0, or 10.0.0.0/8 This network is aprivate address space that has 24 host bits that can be used.

■

172.16.0.0 with a subnet mask of 255.240.0.0, or 172.16.0.0/12 This net-work is a private address space that has 20 host bits that can be used.This providesa range of 16 class B network IDs from 172.0.0.0/16 through 172.31.0.0./16.

■

192.168.0.0 with a subnet mask of 255.255.0.0, 192.168.0.0./16 This net-work is a private address space that has 16 host bits that can be used.This providesa range of 256 class C network IDs from 192.168.0.0/24 through