Each bit in each octet is assigned a decimal value. The result is that IP addresses contain 32 bits. IPv4Īn IPv4 address is composed of four sets of 8 binary bits, which are called octets. The discussion begins by looking at IPv4. IP addressing is different in IPv4 and IPv6. In IP addressing, another set of numbers, called a subnet mask, defines which portion of the IP address refers to the network address and which refers to the node address. All the devices on that network segment must then have different node addresses. It’s a bit like a street name and house number in a person’s home address.Įach device on a logical network segment must have the same network address as all the other devices on the segment. In other words, the IP address provides two pieces of information.

The address defines both the number of the network to which the device is attached and the number of the node on that network. To communicate on a network using TCP/IP, each system must be assigned a unique address. The following sections look at how IP addressing works for both IPv4 and the newest version of IP: IPv6. Fortunately, the Network+ exam requires only a fundamental knowledge of IP addressing. It can leave even the most seasoned network administrators scratching their heads. IP addressing is one of the most challenging aspects of TCP/IP. A private network is any network to which access is restricted.Class C addresses span from 192 to 223, with a default subnet mask of 255.255.255.0.A Class A address uses only the first octet to represent the network portion, a Class B address uses two octets, and a Class C address uses three octets.What are the reserved IPv4 ranges for private networks?.

What is the range that Class C addresses span in the first octet?.

How many octets does a Class A address use to represent the network portion?.

If you can correctly answer these questions before going through this section, save time by skimming the Exam Alerts in this section and then complete the Cram Quiz at the end of the section.

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