Using the private network 10.0.0.0, designing a summarized addressing scheme is straightforward.

When the last three octets are written in binary notation, it is easy to determine the bit allocation needed to fulfill the requirements.

Location Campus Building Floor Hosts

### 0000 I 0000 I .0000 I 0000 I .00000000

This design provides 16 locations, 16 campuses, and 16 buildings. To conform to the rule that excludes the use of all zeros and all ones in a subnet range, you would allocate 14 subnets per building. This would allow 254 hosts per floor or building subnet. Therefore, there is a lot of flexibility in this design for future growth. Draw the topology map for one of the locations.

1 Draw the topology map for one of the locations. See Figure 3-18.

2 Using the private network 10.0.0.0, design an addressing scheme that can be summarized. Apply the binary notation for the bit allocation to your diagram.

See Figure 3-18.

Figure 3-18 Topology Map of One of the Locations

Figure 3-18 Topology Map of One of the Locations

3 List the range of hosts on one of the subnets allocated to a floor in a building. If one of the floors is given the subnet

Location Campus Building Floor Hosts

0000 | 0000 | .0000 | 0000. | .00000000 Subnet in binary notation: 00001010.00010010.00100010.00000000 Subnet in decimal notation:

10.18.34.0

Range of hosts on that subnet:

4 Indicate how summarization would work within the location.

Summarization would work within a location because every device and subnet would share the same 4 high-order bits. The following example clearly demonstrates this:

Location Campus Building Floor Hosts

0000 I 0000 I .0000 I 0000. I .00000000

Subnet in binary notation: 00001010.00010010.00100010.00000000 Subnet in decimal notation: 10.18.34.0

The summarized address advertised out of the location router would be 10.16.0.0/12.

5 Allocate a subnet to be used for VLSM to address the WAN links between the locations.

Many spare subnets are available in the addressing scheme designed. To address the WAN links, it would be sensible to select one of the subnets allocated to the floors and to reassign it to be further subnetted. For example:

Location Campus Building Floor Hosts

0000 0000 .0000 0000. .00000000 Subnet in binary notation: 1000 0000 .1000 1000 .00000000 Subnet in decimal notation: 10.128.128.0/30

This allows 60 subnets, with each subnet allowing two hosts (ideal for point-to-point lines). The use of 128.128 in the second and third octets eases network management by readily identifying the serial connections.

6 Is it possible to summarize the WAN subnets?

It would not be easy to summarize these WAN subnets because they have a longer bit pattern than the other subnets beneath them. If summarization is possible, they could be summarized down to 10.128.128.0. It is equally sensible to use any easily recognizable address for WAN links (for example, 10.100.100.0).