This format is called dotted quad notation. IP addresses are grouped into a network number and a host number. The local network manager will supply the needed numbers for your configuration. Conduct a check on learning and summarize the learning activity. Networks are divided into four classes, depending on the size of the network.
Any network can be a standalone net or a sub-network of another net.
Class A networks are numbered 1.x.x.x through 126.x.x.x. The first octet is the network number. This supports 126 networks, each with roughly 16 million hosts. The first two octets contain the network number. This allows for 16384 nets with 65534 hosts each.