8.2.1.4 Packet Tracer – Designing and Implementing a VLSM Addressing Scheme

Last Updated on March 13, 2018 by Admin

8.2.1.4 Packet Tracer – Designing and Implementing a VLSM Addressing Scheme

Packet Tracer – Designing and Implementing a VLSM Addressing Scheme (Answer Version)

Answer Note: Red font color or gray highlights indicate text that appears in the Answer copy only.

Topology

You will receive one of three possible topologies.

Addressing Table

Device Interface IP Address Subnet Mask Default Gateway
[[R1Name]] G0/0 [[R1G0Add]] [[R1G0Sub]] N/A
G0/1 [[R1G1Add]] [[R1G1Sub]] N/A
S0/0/0 [[R1S0Add]] [[R1S0Sub]] N/A
[[R2Name]] G0/0 [[R2G0Add]] [[R2G0Sub]] N/A
G0/1 [[R2G1Add]] [[R2G1Sub]] N/A
S0/0/0 [[R2S0Add]] [[R2S0Sub]] N/A
[[S1Name]] VLAN 1 [[S1Add]] [[S1Sub]] [[R1G0Add]]
[[S2Name]] VLAN 1 [[S2Add]] [[S2Sub]] [[R1G1Add]]
[[S3Name]] VLAN 1 [[S3Add]] [[S3Sub]] [[R2G0Add]]
[[S4Name]] VLAN 1 [[S4Add]] [[S4Sub]] [[R2G1Add]]
[[PC1Name]] NIC [[PC1Add]] [[PC1Sub]] [[R1G0Add]]
[[PC2Name]] NIC [[PC2Add]] [[PC2Sub]] [[R1G1Add]]
[[PC3Name]] NIC [[PC3Add]] [[PC3Sub]] [[R2G0Add]]
[[PC4Name]] NIC [[PC4Add]] [[PC4Sub]] [[R2G1Add]]

Objectives

Part 1: Examine the Network Requirements

Part 2: Design the VLSM Addressing Scheme

Part 3: Assign IP Addresses to Devices and Verify Connectivity

Background

In this activity, you are given a /24 network address to use to design a VLSM addressing scheme. Based on a set of requirements, you will assign subnets and addressing, configure devices and verify connectivity.

Part 1: Examine the Network Requirements

Step 1: Determine the number of subnets needed.

You will subnet the network address [[DisplayNet]]. The network has the following requirements:

  • [[S1Name]] LAN will require [[HostReg1]] host IP addresses
  • [[S2Name]] LAN will require [[HostReg2]] host IP addresses
  • [[S3Name]] LAN will require [[HostReg3]] host IP addresses
  • [[S4Name]] LAN will require [[HostReg4]] host IP addresses

How many subnets are needed in the network topology? 5

Step 2: Determine the subnet mask information for each subnet.

  1. Which subnet mask will accommodate the number of IP addresses required for [[S1Name]]?
    • How many usable host addresses will this subnet support?
  2. Which subnet mask will accommodate the number of IP addresses required for [[S2Name]]?
    • How many usable host addresses will this subnet support?
  3. Which subnet mask will accommodate the number of IP addresses required for [[S3Name]]?
    • How many usable host addresses will this subnet support?
  4. Which subnet mask will accommodate the number of IP addresses required for [[S4Name]]?
    • How many usable host addresses will this subnet support?
  5. Which subnet mask will accommodate the number of IP addresses required for the connection between [[R1Name]] and [[R2Name]]?

Part 2: Design the VLSM Addressing Scheme

Step 1: Divide the [[DisplayNet]] network based on the number of hosts per subnet.

  1. Use the first subnet to accommodate the largest LAN.
  2. Use the second subnet to accommodate the second largest LAN.
  3. Use the third subnet to accommodate the third largest LAN.
  4. Use the fourth subnet to accommodate the fourth largest LAN.
  5. Use the fifth subnet to accommodate the connection between [[R1Name]] and [[R2Name]].

Step 2: Document the VLSM subnets.

Complete the Subnet Table, listing the subnet descriptions (e.g. [[S1Name]] LAN), number of hosts needed, then network address for the subnet, the first usable host address, and the broadcast address. Repeat until all addresses are listed.

Subnet Table

Note: The correct answers for this table are variable depending on the scenario received. Refer to the Answer Notes at the end of these instructions for further information. The format here follows what the student used in Designing and Implementing a VLSM Addressing Scheme.

Subnet Description Number of Hosts Needed Network Address/CIDR First Usable Host Address Broadcast Address

Step 3: Document the addressing scheme.

  1. Assign the first usable IP addresses to [[R1Name]] for the two LAN links and the WAN link.
  2. Assign the first usable IP addresses to [[R2Name]] for the two LANs links. Assign the last usable IP address for the WAN link.
  3. Assign the second usable IP addresses to the switches.
  4. Assign the last usable IP addresses to the hosts.

Part 3: Assign IP Addresses to Devices and Verify Connectivity

Most of the IP addressing is already configured on this network. Implement the following steps to complete the addressing configuration.

Step 1: Configure IP addressing on [[R1Name]] LAN interfaces.

Step 2: Configure IP addressing on [[S3Name]], including the default gateway.

Step 3: Configure IP addressing on [[PC4Name]], including the default gateway.

Step 4: Verify connectivity.

You can only verify connectivity from [[R1Name]], [[S3Name]], and [[PC4Name]]. However, you should be able to ping every IP address listed in the Addressing Table.

Suggested Scoring Rubric

Note: The majority of points are allocated to designing and documenting the addressing scheme. Implementation of the addresses in Packet Tracer is of minimal consideration.

Activity Section Question Location Possible Points Earned Points
Part 1: Examine the Network Requirements Step 1 1
Step 2 4
Part 1 Total 5
Part 2: Design the VLSM Addressing Scheme
Complete Subnet Table 25
Document Addressing 40
Part 2 Total 65
Packet Tracer Score 30
Total Score 100

ID:[[indexAdds]][[indexNames]][[indexTopos]]

Answer Notes:

The following addressing tables represent the three possible addressing scenarios the student may get. Note that the Device column is independent of the addressing scheme. For example, a student could receive the device names from Scenario 1 and the addressing scheme from Scenario 3. In addition, the three possible topologies are also independent of the device names and the addressing scheme (click reset in the activity to see the different topologies). Therefore, this activity uses three independent variables with three possible values each for a total of 27 possible combinations (3 device names x 3 addressing schemes x 3 topologies = 27 isomorphs).

Scenario 1 – Network Address: 10.11.48.0/24

Subnet Table

Subnet Description Number of Hosts Needed Network Address/CIDR First Usable Host Address Last Usable Host Address Broadcast Address
Host-D LAN 60 10.11.48.0/26 10.11.48.1 10.11.48.62 10.11.48.63
Host-B LAN 30 10.11.48.64/27 10.11.48.65 10.11.48.94 10.11.48.95
Host-A LAN 14 10.11.48.96/28 10.11.48.97 10.11.48.110 10.11.48.111
Host-C LAN 6 10.11.48.112/29 10.11.48.113 10.11.48.118 10.11.48.119
WAN Link 2 10.11.48.120/30 10.11.48.121 10.11.48.122 10.11.48.123
Device Interface Address Subnet Mask Default Gateway
Building1 G0/0 10.11.48.97 255.255.255.240 N/A
G0/1 10.11.48.65 255.255.255.224 N/A
S0/0/0 10.11.48.121 255.255.255.252 N/A
Building2 G0/0 10.11.48.113 255.255.255.248 N/A
G0/1 10.11.48.1 255.255.255.192 N/A
S0/0/0 10.11.48.122 255.255.255.252 N/A
ASW1 VLAN 1 10.11.48.98 255.255.255.240 10.11.48.97
ASW2 VLAN 1 10.11.48.66 255.255.255.224 10.11.48.65
ASW3 VLAN 1 10.11.48.114 255.255.255.248 10.11.48.113
ASW4 VLAN 1 10.11.48.2 255.255.255.192 10.11.48.1
Host-A NIC 10.11.48.110 255.255.255.240 10.11.48.97
Host-B NIC 10.11.48.94 255.255.255.224 10.11.48.65
Host-C NIC 10.11.48.118 255.255.255.248 10.11.48.113
Host-D NIC 10.11.48.62 255.255.255.192 10.11.48.1

Building 1

en

conf t

int g0/0

ip add 10.11.48.97 255.255.255.240

no shut

int g0/1

ip add 10.11.48.65 255.255.255.224

no shut

ASW3

en

conf t

int vlan 1

ip add 10.11.48.114 255.255.255.248

no shut

ip def 10.11.48.113

Scenario 2 – Network Address: 172.31.103.0/24

Subnet Table

Subnet Description Number of Hosts Needed Network Address/CIDR First Usable Host Address Last Usable Host Address Broadcast Address
PC-A LAN 27 172.31.103.0/27 172.31.103.1 172.31.103.30 172.31.103.31
PC-B LAN 25 172.31.103.32/27 172.31.103.33 172.31.103.62 172.31.103.63
PC-C LAN 14 172.31.103.64/28 172.31.103.65 172.31.103.78 172.31.103.79
PC-D LAN 8 172.31.103.80/28 172.31.103.81 172.31.103.94 172.31.103.95
WAN Link 2 172.31.103.96/30 172.31.103.97 172.31.103.98 172.31.103.99

 

Device Interface Address Subnet Mask Default Gateway
Branch1 G0/0 172.31.103.1 255.255.255.224 N/A
G0/1 172.31.103.33 255.255.255.224 N/A
S0/0/0 172.31.103.97 255.255.255.252 N/A
Branch2 G0/0 172.31.103.65 255.255.255.240 N/A
G0/1 172.31.103.81 255.255.255.240 N/A
S0/0/0 172.31.103.98 255.255.255.252 N/A
Room-114 VLAN 1 172.31.103.2 255.255.255.224 172.31.103.1
Room-279 VLAN 1 172.31.103.34 255.255.255.224 172.31.103.33
Room-312 VLAN 1 172.31.103.66 255.255.255.240 172.31.103.65
Room-407 VLAN 1 172.31.103.82 255.255.255.240 172.31.103.81
PC-A NIC 172.31.103.30 255.255.255.224 172.31.103.1
PC-B NIC 172.31.103.62 255.255.255.224 172.31.103.33
PC-C NIC 172.31.103.78 255.255.255.240 172.31.103.65
PC-D NIC 172.31.103.94 255.255.255.240 172.31.103.81

Branch 1

en

conf t

int g0/0

ip add 172.31.103.1 255.255.255.224

no shut

int g0/1

ip add 172.31.103.33 255.255.255.224

no shut

Room-312

en

conf t

int vlan 1

ip add 172.31.103.66 255.255.255.240

no shut

ip def 172.31.103.65

Scenario 3 – Network Address: 192.168.72.0/24

Subnet Table

Subnet Description Number of Hosts Needed Network Address/CIDR First Usable Host Address Last Usable Host Address Broadcast Address
User-4 LAN 58 192.168.72.0/26 192.168.72.1 192.168.72.62 192.168.72.63
User-3 LAN 29 192.168.72.64/27 192.168.72.65 192.168.72.94 192.168.72.95
User-2 LAN 15 192.168.72.96/27 192.168.72.97 192.168.72.126 192.168.72.127
User-1 LAN 7 192.168.72.128/28 192.168.72.129 192.168.72.142 192.168.72.143
WAN Link 2 192.168.72.144/30 192.168.72.145 192.168.72.146 192.168.72.147

 

Device Interface Address Subnet Mask Default Gateway
Remote-Site1 G0/0 192.168.72.129 255.255.255.240 N/A
G0/1 192.168.72.97 255.255.255.224 N/A
S0/0/0 192.168.72.145 255.255.255.252 N/A
Remote-Site2 G0/0 192.168.72.65 255.255.255.224 N/A
G0/1 192.168.72.1 255.255.255.192 N/A
S0/0/0 192.168.72.146 255.255.255.252 N/A
Sw1 VLAN 1 192.168.72.130 255.255.255.240 192.168.72.129
Sw2 VLAN 1 192.168.72.98 255.255.255.224 192.168.72.97
Sw3 VLAN 1 192.168.72.66 255.255.255.224 192.168.72.65
Sw4 VLAN 1 192.168.72.2 255.255.255.192 192.168.72.1
User-1 NIC 192.168.72.142 255.255.255.240 192.168.72.129
User-2 NIC 192.168.72.126 255.255.255.224 192.168.72.97
User-3 NIC 192.168.72.94 255.255.255.224 192.168.72.65
User-4 NIC 192.168.72.62 255.255.255.192 192.168.72.1

Remote-Site1

en

conf t

int g0/0

ip add 192.168.72.129 255.255.255.240

no shut

int g0/1

ip add 192.168.72.97 255.255.255.224

no shut

Sw-3

en

conf t

int vlan 1

ip add 192.168.72.66 255.255.255.224

no shut

ip def 192.168.72.65