Computer Networks Lab exercise 2
Lab exercise 2
Objectives
Upon completion of this lab, you will be able to: • Using Packet Tracer to build computer networks • Cable networks according to the topology diagram • Configure end devices • Perform basic configuration tasks on routers • Verify configuration and network connectivity • Troubleshooting simple network issues
Instructions
This lab aims to build several connected networks as shown in Figure 1, following detailed step by step instructions on configuration and verification. This lab is not assessed, but it is essential to go through all steps in order to complete later labs in the module. In particular, Lab 3 in week 9 will require you to use the same process to build networks in a different given scenario.
Figure 1 Network topology diagram
Step 1 : Add network devices to the workspace
Using the Device -Type Selection Box, add the following devices to the workspace. • Add three 1841 routers. Under the ‘Physical’ tab, add in 2 modules with Ethernet ports (W1C -1ENET) for each router. You will need to turn the routers off when adding the modu les. Remember to switch the routers back on when complete. • Add three generic PCs.
Step 2 : Add physical cabling between devices in the workspace.
• Using the Device -Type Selection Box, click ‘Connections’ and choose ‘Copper crossover’ wire the routers as shown in Figure 1. Go to the menu: Options ->preferences ->Always show port labels in logical workspace to display port labels. • Make sure you have all the interfaces correctly wired and that you used the correct wire.
Step 3 : Configure the end devices and routers.
• Configure the three PCs. Click on the PC. In the ‘Desktop’ tab, navigate to ‘IP Configuration’, assign the relevant IP address and subnet mask as given in the Addressing table below. For each PC, you must also configure its ‘Default Gateway’ ad dress. This is the address of the router interface that the PC is directly connected to. You need to work this out by looking at the Addressing table and the topology diagram.
• Configure the interfaces of the three routers. Click on the router. In the ‘C onfig’ tab, select the relevant interface, assign the relevant IP address and subnet mask as given in the Addressing table below. Make sure the ‘Port Status’ is ‘on’. (If both ends of a connection are switched on they are green – if they are red they are o ff). Device Port IP Subnet mask PC 0 Fa0 192.168.0.1 255.255.255.0 PC 1 Fa1 192.168.1.1 255.255.255.0 PC 2 Fa2 192.168.2.1 255.255.255.0 Router 0 Fa0/0 192.168.0.2 255.255.255.0 Router 0 Fa0/1 192.168.3.1 255.255.255.0 Router 0 Eth0/0/0 192.168.4.1 255.255.255.0 Router 1 Fa0/0 192.168.1.2 255.255.255.0 Router 1 Eth0/0/0 192.168.4.2 255.255.255.0 Router 1 Eth0/1/0 192.168.5.1 255.255.255.0 Router 2 Fa0/0 192.168.2.2 255.255.255.0 Router 2 Fa0/1 192.168.3.2 255.255.255.0 Router 2 Eth0/1/0 192.168.5.2 255.255.255.0
Step 4 : Test the PC configuration
• You can test the PC configuration by pinging the default gateway from the PC. Click on the PC0. In the ‘Desktop’ tab, open the ‘Command Prompt’, type: ping 192.168.0.2 If the configuration is correct you should get four replies Reply from 192.168.0.2: bytes=32 time=0ms TTL=255 Reply from 192.168.0.2: bytes=32 time=0ms TTL=255 Reply from 192.168.0.2: bytes=32 time=0ms TTL=255 Reply from 192.168.0.2: bytes=32 time=0ms TTL=255 You can also check the route by typing: tracert 192.168.0.2 If the configuration is correct you should see the following Tracing route to 192.168.0.2 over a maximum of 30 hops: 1 0 ms 0 ms 0 ms 192.168.0.2 Trace complete. • Test PC1 and PC2 configuration by pinging their relevant default gateway addresses.
Troubleshooting : If you don’t receive successful ping and tracert replies, check the following: 1) Are the routers switched on? Check the ‘on/off’ button under the ‘Physical Device View’ in the ‘Physical’ tab of the routers. If the router is on, there will be a green light on the ‘on/off’ button. 2) Are all the interfaces on? Check the ‘Port Status’ of the interface under the ‘Config’ tab of the routers. 2) Are the IP a ddresses set correctly according to the Addressing table? 3) Have all PCs been configured with their default gateway addresses correctly? 4) Are all subnet masks set to 255.255.255.0 (same as a /24)?
Although now all three PCs have been connected to the routers and the three routers are interconnected, it will NOT be possible for the three PCs to communicate with each other. You can test this by pinging PC1 from PC0. Go to PC0, type: ping 192.168.1.2
You will not get a response from PC2 and you should se e the following: Pinging 192.168.1.2 with 32 bytes of data:
Reply from 192.168.0.2: Destination host unreachable. Reply from 192.168.0.2: Destination host unreachable. Reply from 192.168.0.2: Destination host unreachable. Reply from 192.168.0.2: Des tination host unreachable.
Ping statistics for 192.168.1.2: Packets: Sent = 4, Received = 0, Lost = 4 (100% loss),
Step 5 : Set up routing by configure RIP1 at the routers
• Click on Router0, select ‘RIP’ under the ‘Config’ tab, add the network 192.168.0.0, 192.168.3.0 and 192.168.4.0.
• Repeat the above process for Router1 and Router2. Make sure you add the correct networks to the relevant routers based on the topology diag ram.
Step 6 : Verify routing operation
• You can verify the RIP configuration and the network connectivity by pinging a PC on a different network. Click on PC0, type: ping 192.168.2.1 If the configuration is correct you should see the following Pinging 192.168.2.1 with 32 bytes of data:
Reply from 192.168.2.1: bytes=32 time=0ms TTL=126 Reply from 192.168.2.1: bytes=32 time=0ms TTL=126
1 RIP: Routing Information Protocol. RIP is the simplest and one of the oldest Distance Vector routing protocol used in the Internet. Reply from 192.168.2.1: bytes=32 time=0ms TTL=126 Reply from 192.168.2.1: bytes=32 time=0ms TTL=126
Ping statistics for 192.168.2.1: Packets: Sent = 4, Received = 4, Lost = 0 (0% loss), Approximate round trip times in milli -seconds: Minimum = 0ms, Maximum = 0ms, Average = 0ms
You can also use tracert to trace the route from PC0 to PC2, type: tracert 192.168.2.1
If the configuration is correct you should see the following
Tracing route to 192.168.2.1 over a maximum of 30 hops:
1 1 ms 0 ms 0 ms 192.168.0.2 2 0 ms 0 ms 0 ms 192.168.3.2 3 0 ms 0 ms 0 ms 192.168.2.1
Trace complete.
