IFN507 Network Systems P4: Subnetting and Supernetting
Practical 4
Subnetting and Supernetting
Learning Objectives
Upon completion of this practical, you will be able to:
· Implement a subnetting scheme with Packet Tracer
Scenario
· Lab Activity 1: Implement a network scenario with 4 subnets
· Lab Activity 2: Implement a network scenario with 8 subnets
· More exercises on subnetting and supernetting
Lab Activity 1 – Implement a Network with 4 Subnets
In this activity, you will design an IP addressing scheme for the topology shown in Figure 1, and then implement the IP addressing scheme with Packet Tracer.
Activity Objectives:
· Subnet the address space
· Configure IP addresses with Packet Tracer
· Summarise routes through configuring aggregate routes
Topology Diagram
Figure 1 Network Topology
Addressing Table 1
Device
Interface
IP Address
Subnet Mask
Default Gateway
ISP
Se2/0
200.0.0.2
255.255.255.0
N/A
BR
Se2/0
200.0.0.1
255.255.255.0
N/A
Se3/0
193.64.33.1
255.255.255.192
N/A
Fa0/0
193.64.33.65
255.255.255.192
N/A
HQ
Se2/0
193.64.33.2
255.255.255.192
N/A
Fa0/0
193.64.33.129
255.255.255.192
N/A
Fa1/0
193.64.33.193
255.255.255.192
N/A
DNS
NIC
193.64.33.66
255.255.255.192
193.64.33.65
HTTP
NIC
193.64.33.67
255.255.255.192
193.64.33.65
PC1
NIC
193.64.33.130
255.255.255.192
193.64.33.129
PC2
NIC
193.64.33.190
255.255.255.192
193.64.33.129
PC3
NIC
193.64.33.194
255.255.255.192
193.64.33.193
PC4
NIC
193.64.33.254
255.255.255.192
193.64.33.193
Note: Fill the missing contents in the diagram and in the above Addressing Table 1
Task 1: Subnet the Address Space
Step 1: Examine the network requirements
ABC company has been given the 193.64.33.0/24 address space. You are employed to restructure ABC’s network. You need to set up an addressing scheme that can accommodate for the Internet access and data sharing between the four LANs. Each LAN needs to be on a separate network (subnet).
· The link between routers BR (border) and HQ (headquarters) would need enough IP addresses to support 32 hosts.
· The SE (servers) LAN would need enough IP addresses to support 40 hosts.
· The SA (sales) LAN would need enough IP addresses to support 50 hosts.
· The HR (human resource) LAN would need enough IP addresses to support 60 hosts.
Note: The plan should have equal size subnets and use the smallest subnet sizes that will accommodate the appropriate number of hosts.
Step 2: Consider the following questions when creating your network design
Q1: How many subnets are needed? 4.
Q2: How many bits you need to borrow from the host portion for subnetting? 2.
Q3: What is the subnet mask used for this subnetting scheme in dotted-decimal notation? 255.255.255.192 and in slash notation /26
Q4: What is the maximum number of usable IP addresses per subnet? 26 – 2 = 62
Step 3: Use the following table to list out the subnet information in decimal notation
Subnet
Network
Address
Slash Notation
First Usable
IP Address
Last Usable
IP Address
Broadcast Address
1
193.64.33.0
/26
193.64.33.1
193.64.33.62
193.64.33.63
2
193.64.33.64
/26
193.64.33.65
193.64.33.126
193.64.33.127
3
193.64.33.128
/26
193.64.33.129
193.64.33.190
193.64.33.191
4
193.64.33.192
/26
193.64.33.193
193.64.33.254
193.64.33.255
Task 2: Assign IP Addresses
1. Fill in Addressing Table 1 with IP addressing information based on the IP address requirements mentioned below:
Subnet 1 is used for the link between routers BR and HQ:
· Assign the first usable IP address of Subnet 1 to the Se3/0 interface of BR.
· Assign the second usable IP address of Subnet 1 to the Se2/0 interface of HQ.
Subnet 2 for the SE LAN:
· Assign the first usable IP address of Subnet 2 to the Fa0/0 interface of BR
· Assign the second usable IP address of Subnet 2 to the DNS server
· Assign the third usable IP address of Subnet 2 to the HTTP server
Subnet 3 for the SA LAN:
· Assign the first usable IP address of Subnet 3 to the Fa0/0 interface of HQ.
· Assign the second usable IP address of Subnet 3 to PC1
· Assign the last usable IP address of Subnet 3 to PC2
Subnet 4 for the HR LAN:
· Assign the first usable IP address of Subnet 4 to the Fa1/0 interface of HQ.
· Assign the second usable IP address of Subnet 4 to PC3
· Assign the last usable IP address of Subnet 4 to PC4
2. Record the dedicated IP addresses in Addressing Table 1.
Task 3: Build the Network Topology
Use Packet Tracer to build the network topology as shown in Figure 1.
Task 4: Configure IP Addressing
Use Addressing Table 1 to configure dedicated IP addresses to the routers and PCs.
Configuring the IP addresses for Router ISP
Router>enable
Router# configure terminal
Router(config)#hostname ISP
ISP(config)# interface Se2/0
ISP(config-if)# ip address 200.0.0.2 255.255.255.0
ISP(config-if)# exit
ISP(config)#
Configuring the IP addresses for Router BR
Router>enable
Router# configure terminal
Router(config)# hostname BR
BR(config)#interface Se2/0
BR(config-if)# ip add 200.0.0.1 255.255.255.0
BR(config-if)#exit
BR(config)#interface Se3/0
BR(config-if)#ip add 193.64.33.1 255.255.255.192
BR(config-if)#exit
BR(config)#interface Fa0/0
BR(config-if)#ip add 193.64.33.65 255.255.255.192
Configuring the IP addresses for Router HQ
Router>enable
Router# configure terminal
Router(config)# hostname HQ
HQ(config)#interface Se2/0
HQ(config-if)# ip add 193.64.33.2 255.255.255.192
HQ(config-if)#exit
HQ(config)#interface Fa0/0
HQ(config-if)#ip add 193.64.33.129 255.255.255.192
HQ(config-if)#exit
HQ(config)#interface Fa1/0
HQ(config-if)#ip add 193.64.33.193 255.255.255.192
Task 5: Verify Connectivity
Step 1: Test connectivity between directly connected devices
· From router ISP, can you ping the interface Se2/0 of BR successfully? Yes / No
· From router BR, can you ping the interface Se2/0 of HQ successfully? Yes / No
· From each server, can you ping its default gateway successfully? Yes / No
· From each PC, can you ping its default gateway successfully? Yes / No
If you cannot ping successfully at any points, verify the following:
1. Check the cable connection. Have you used the correct Ethernet cables for network connections?
2. Check the router interfaces. Have you activated routers interfaces?
3. Check your IP address configuration. Is your IP address configuration consistent with the Topology Diagram and Addressing Table? Have you configured a default gateway for each PC?
4. Check the subnet information. Is your subnetting scheme calculated correctly?
Step 2: Test connectivity between devices that are NOT on the same network
· From PC4, can you ping PC1 successfully? Yes / No
· From PC4, you are unable to ping the HTTP server successfully. Why?
PC4 pings HTTP failed because HQ doesn’t have a route to reach network 193.64.33.64/26, and BR doesn’t have a route to reach network 193.64.33.192/26.
· From PC4, you are unable to ping the interface Se2/0 of ISP router. Why?
PC4 cannot ping ISP Se2/0 because HQ doesn’t have a route to reach network 200.0.0.0/24, and ISP doesn’t have a route to reach networks 193.64.33.0/26 and 193.64.33.192/26.
Task 7: Save your work
Click the File menu and then Save your network topology with a file name: Lab4.1.
NOTE: You will need to work with this network topology configuration in the next practical session to resolve the connectivity issue between devices that are NOT on the same network.
Lab Activity 2
In this activity, you will design an IP addressing scheme for the topology shown in Figure 2, and then implement the IP addressing scheme with Packet Tracer.
Activity Objectives:
· Subnet the address space
· Configure IP addresses with Packet Tracer
· Summarise routes through configuring aggregate routes
Topology Diagram
Figure 2 Network Topology
Addressing Table 2
Device
Interface
IP Address
Subnet Mask
Default Gateway
ISP
Se2/0
200.0.0.2
255.255.255.0
N/A
BR
Se2/0
200.0.0.1
255.255.255.0
N/A
Se3/0
193.64.33.1
255.255.255.224
N/A
Fa0/0
193.64.33.33
255.255.255.224
N/A
Fa1/0
193.64.33.65
255.255.255.224
N/A
HQ
Se2/0
193.64.33.2
255.255.255.224
N/A
Fa0/0
193.64.33.129
255.255.255.224
N/A
Fa1/0
193.64.33.161
255.255.255.224
N/A
Fa4/0
193.64.33.193
255.255.255.224
N/A
DNS
NIC
193.64.33.34
255.255.255.224
193.64.33.33
HTTP
NIC
193.64.33.66
255.255.255.224
193.64.33.65
SA-PC1
NIC
193.64.33.158
255.255.255.224
193.64.33.129
FS-PC1
NIC
193.64.33.190
255.255.255.224
193.64.33.161
HR-PC1
NIC
193.64.33.222
255.255.255.224
193.64.33.193
Note: Fill the missing contents in the diagram and in the above addressing table 2
Task 1: Subnet the Address Space
Step 1: Examine the network requirements
XYZ company has been given the 193.64.33.0/24 address space. You are employed to restructure XYZ’s network. You need to set up an addressing scheme that can accommodate for the Internet access and data sharing between the LANs. Each LAN needs to be on a separate network (subnet).
· The link between routers BR (border) and HQ (headquarters) would need enough IP addresses to support 16 hosts.
· The SE1 (servers 1) LAN would need enough IP addresses to support 20 hosts.
· The SE2 (servers 2) LAN would need enough IP addresses to support 22 hosts.
· The SA (sales) LAN would need enough IP addresses to support 30 hosts.
· The FS (field service) LAN would need enough IP addresses to support 28 hosts.
· The HR (human resource) LAN would need enough IP addresses to support 18 hosts.
Note: The plan should have equal size subnets and use the smallest subnet sizes that will accommodate the appropriate number of hosts.
Step 2: Consider the following questions when creating your network design
Q1: How many subnets are needed? 6
Q2: How many bits you need to borrow from the host portion for subnetting? 3
Q3: How many subnets will be created when you borrowed the Host-ID bits? 8
Q4: What is the subnet mask used for this addressing scheme in dotted-decimal notation? 255.255.255.224
Q5: What is the subnet mask used for this addressing scheme in slash notation? /27
Q6: What is the maximum number of usable IP addresses per subnet? 25 – 2 = 30
Step 3: Use the following table to list out the subnet information in decimal notation.
Subnet
Network
Address
Slash Notation
First Usable
IP Address
Last Usable
IP Address
Broadcast Address
1
193.64.33.0
/27
193.64.33.1
193.64.33.30
193.64.33.31
2
193.64.33.32
/27
193.64.33.33
193.64.33.62
193.64.33.63
3
193.64.33.64
/27
193.64.33.65
193.64.33.94
193.64.33.95
4
193.64.33.96
/27
193.64.33.97
193.64.33.126
193.64.33.127
5
193.64.33.128
/27
193.64.33.129
193.64.33.158
193.64.33.159
6
193.64.33.160
/27
193.64.33.161
193.64.33.190
193.64.33.191
7
193.64.33.192
/27
193.64.33.193
193.64.33.222
193.64.33.223
8
193.64.33.224
/27
193.64.33.225
193.64.33.254
193.64.33.255
Task 2: Assign IP Addresses
1. Fill in Addressing Table 2 with IP addressing information based on the IP address requirements mentioned below:
Subnet 1 for the link between routers BR and HQ:
· Assign the first usable IP address of Subnet 1 to the interface Se3/0 of BR.
· Assign the second usable IP address of Subnet 1 to the interface Se2/0 of HQ.
Subnet 2 for the SE1 LAN:
· Assign the first usable IP address of Subnet 2 to the interface Fa0/0 of BR.
· Assign the second usable IP address of Subnet 2 to the DNS server
Subnet 3 for the SE2 LAN:
· Assign the first usable IP address of Subnet 3 to the interface Fa1/0 of BR.
· Assign the second usable IP address of Subnet 3 to the HTTP server.
Subnet 4 is reserved for future use.
Subnet 5 for the SA LAN:
· Assign the first usable IP address of Subnet 5 to the interface Fa0/0 of HQ.
· Assign the last usable IP address of Subnet 5 to SA-PC1
Subnet 6 for the FS LAN:
· Assign the first usable IP address of Subnet 6 to the interface Fa1/0 of HQ.
· Assign the last usable IP address of Subnet 6 to FS-PC1
Subnet 7 for the HR LAN:
· Assign the first usable IP address of Subnet 7 to the interface Fa4/0 of HQ.
· Assign the last usable IP address of Subnet 7 to HR-PC1
Subnet 8 is reserved for future use.
2. Record the dedicated IP addresses in Addressing Table 2.
Q7: Which two subnets are not used based on this IP addressing assignment? Subnets 4 and 8
Task 3: Build the Network Topology
Use Packet Tracer to build the network topology as shown in Figure 2.
Task 4: Configure IP Addressing
Use the Addressing Table 2 to configure dedicated IP addresses to the routers and PCs.
Configuring the IP addresses for Router ISP
Router>enable
Router# configure terminal
Router(config)#hostname ISP
ISP(config)# interface Se2/0
ISP(config-if)# ip add 200.0.0.2 255.255.255.0
ISP(config-if)# exit
ISP(config)#
Configuring the IP addresses for Router BR
Router>enable
Router# configure terminal
Router(config)#hostname BR
BR(config)#interface Se2/0
BR(config-if)# ip add 194.32.33.1 255.255.255.224
BR(config-if)#exit
BR(config)#interface Se3/0
BR(config-if)#ip add 193.64.33.1 255.255.255.224
BR(config-if)#exit
BR(config)# interface Fa0/0
BR(config-if)#ip add 193.64.33.33 255.255.255.224
BR(config-if)#exit
BR(config)interface Fa1/0
BR(config-if)#ip add 193.64.33.65 255.255.255.224
Configuring the IP addresses for Router HQ
Router>enable
Router# configure terminal
Router(config)#hostname HQ
HQ(config)#interface Se2/0
HQ(config-if)# ip add 193.64.33.2 255.255.255.224
HQ(config-if)#exit
HQ(config)#interface Fa0/0
HQ(config-if)#ip add 193.64.33.129 255.255.255.224
HQ(config-if)#exit
HQ(config)# interface Fa1/0
HQ(config-if)#ip add 193.64.33.161 255.255.255.224
HQ(config-if)#exit
HQ(config)interface Fa4/0
HQ(config-if)#ip add 193.64.33.193 255.255.255.224
Task 5: Verify Connectivity
Step 1: Test connectivity between directly connected devices
· From router ISP, can you ping the interface Se2/0 of BR successfully? Yes / No
· From router BR, can you ping the interface Se2/0 of HQ successfully? Yes / No
· From each server, can you ping its default gateway successfully? Yes / No
· From each PC, can you ping its default gateway successfully? Yes / No
If you cannot ping successfully at any points, verify the following:
1. Check the cable connection. Have you used the correct Ethernet cables for network connections?
2. Check the router interfaces. Have you activated routers interfaces?
3. Check your IP address configuration. Is your IP address configuration consistent with the Topology Diagram and Addressing Table? Have you configured a default gateway for each PC?
4. Check the subnet information. Is your subnetting scheme calculated correctly?
Step 2: Test connectivity between devices that are NOT on the same network
· From HR-PC1, can you ping FS-PC1 successfully? Yes / No
· From HR-PC1, can you ping SA-PC1 successfully? Yes / No
· From HR-PC1, you are unable to ping the HTTP server and the DNS server. Why?
From HR-PC1,you cannot ping DNS and HTTP because HQ doesn’t have a route to reach networks 193.64.33.32/27 and 193.64.33.64/27, while BR doesn’t have a route to reach network 193.64.33.160/27
· From HR-PC1, you are unable to ping the interface Se2/0 of ISP successfully? Why?
From HR-PC1, you cannot ping ISP Se2/0 because HQ doesn’t have a route to reach network 200.0.0.0/24. ISP doesn’t have a route to reach networks 193.64.33.0/27 and 193.64.33.160/27.
Task 7: Save your work
Click the File menu and then Save your network topology with a file name: Lab4.2.
NOTE: You will need to work with this network topology configuration in the next practical session to resolve the connectivity issue between devices that are NOT on the same network, so make sure you save this file!!!
More exercises on Subnetting and Supernetting
1. A block of address 194.32.8.0/24 has been given, you need to organise 16 subnets. You need to work out:
· The subnet mask
· The 16 subnets
· The valid host range and broadcast address for each subnet
Subnet mask
255.255.255.240 (11111111.11111111.111111111.11110000)
Subnet
Network address
Valid host range
Broadcast address
1
194.32.8.0/28
194.32.8.1 – 194.32.8.14
194.32.8.15
2
194.32.8.16/28
194.32.8.17 – 194.32.8.30
194.32.8.31
3
194.32.8.32/28
194.32.8.33 – 194.32.8.46
194.32.8.47
4
194.32.8.48/28
194.32.8.9 – 194.32.8.62
194.32.8.63
5
194.32.8.64/28
194.32.8.65 – 194.32.8.78
194.32.8.79
6
194.32.8.80/28
194.32.8.81 – 194.32.8.94
194.32.8.95
7
194.32.8.96/28
194.32.8.97 – 194.32.8.110
194.32.8.111
8
194.32.8.112/28
194.32.8.113 – 194.32.8.126
194.32.8.127
9
194.32.8.128/28
194.32.8.129 – 194.32.8.142
194.32.8.143
10
194.32.8.144/28
194.32.8.145 – 194.32.8.158
194.32.8.159
11
194.32.8.160/28
194.32.8.161 – 194.32.8.174
194.32.8.175
12
194.32.8.176/28
194.32.8.177 – 194.32.8.190
194.32.8.191
13
194.32.8.192/28
194.32.8.193 – 194.32.8.206
194.32.8.207
14
194.32.8.208/28
194.32.8.209 – 194.32.8.222
194.32.8.223
15
194.32.8.224/28
194.32.8.225 – 194.32.8.238
194.32.8.239
16
194.32.8.240/28
194.32.8.241 – 194.32.8.254
194.32.8.255
2. How to aggregate the following network addresses into one single network address notation?
Network addresses
Aggregated Address
200.100.0.0/24
200.100.1.0/24
200.100.0.0/23
200.100.2.0/24
200.100.3.0/24
200.100.2.0/23
200.100.4.0/24
200.100.5.0/24
200.100.6.0/24
200.100.7.0/24
200.100.4.0/22
200.100.0.0/24
200.100.1.0/24
200.100.2.0/24
200.100.3.0/24
200.100.4.0/24
200.100.5.0/24
200.100.6.0/24
200.100.7.0/24
200.100.0.0/21
End of the lab activities
End of Practical 4
Page 1 of 15