172.16 subnet

172.16 subnet belongs to the default class B range that is reserved for private addresses so we can use this range to assign the IP addresses to the devices within our network.

The default subnet of the 172.16 range is 255.255.0.0

The following range is available for the private addressing.

Class B: 172.16.0.0 to 172.31.255.255

By default class b range provides 65,536 addresses so if we reserve one for network ID and the other for broadcast address then we have 65,534 addresses in one network that can be assigned to the host.

65,534 is a huge number of IP address and practically it is not implemented by organizations as nobody have such network that requires this amount of end devices in one network.

The normal recommendation by Cisco is to limit the devices to 500 in one network because more than this will slow down the network as more devices mean more broadcast traffic will be generated along with other types of traffic so a network with thousands of devices is not practical.

Moreover, no one even needs 65534 devices in one subnet. If we will use this range in one network then we will be wasting the IP addresses as we cannot be using the remaining IPs and it will waste a large number of IPs.

To solve this issue, subnetting is used to create many networks from the available range. VLSM can be used to create subnets according to the IP addressing used in the organization. VLSM provides an efficient way to assign IP addresses.

Most of the time, class C subnet mask fulfills the requirement of one network as it provides 254 usable IP addresses in one network however if we need more IPs then we can use subnet mask 255.255.254.0 to increase the available host to 510.

You can check the subnetting examples to see how we can divide one big network and create multiple networks.

In the internal network, the 172.16 range provides enough IPs that can be assigned or used in the large enterprise network that requires thousand of end devices.

To practice, we can create a lab in packet tracer and assign the IP addresses from this range.

In the below image, please find out the missing IP and correct the IP configuration.

172.16 network

172.16 subnet

Answer

172.16.0.0 cannot be used as this address is reserved for the network ID. However, we can use any other IP address from the available 65,534 IPs.

As 172.16.0.0 is subnetted, IP assigned to the PC belongs to a different network so we have to correct the configuration and assign the IP from the following range.
172.16.0.1 to 172.16.0.254

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