Lab-4-2-submission

Simple Routing Lab

Objective: Configure and observe a simple routed network.

Goals:

  • Observe the Layer 2 header changes as a packet crosses a router

  • Recognize the role of the default gateway

Part 1 - Configuring the Network

1. Start by downloading and opening the Packet Tracer file for this lab: lab41-starter.pkt

Download lab41-starter.pkt

2. The network should look something like this:

3. Assign the following IP addresses and subnet masks to the PCs (you should have instructions for doing this in your Tech Journal): What is a subnet mask?

  • PC0

    • IP address: 192.168.1.10

    • Subnet Mask: 255.255.255.0

  • PC1

    • IP address: 192.168.2.20

    • Subnet Mask: 255.255.255.0

  • PC2

    • IP address: 192.168.3.30

    • Subnet Mask: 255.255.255.0

3. Since we'll be pinging across different networks, we'll need to define the gateway addresses for our PCs. To set the gateway for a PC, choose the Config tab, and then choose 'Settings' in the left-hand menu. You can enter the gateway IP in the 'Gateway' field (make sure the 'Static' button above it is selected). Define default gateway?

A gateway is a piece of networking hardware or software used in telecommunications networks that allows data to flow from one discrete network to another.

4. Enter the following gateway IPs for each PC:

  • PC0: 192.168.1.1

  • PC1: 192.168.2.1

  • PC3: 192.168.3.1

5. Now, we'll need to set the interface that each PC is connected to on the multilayer switch to match the gateway IP we just defined, since this switch also has layer 3 routing capabilities and will serve as the gateway for all three machines. Click on the multilayer switch, choose the Config tab in the window that appears, and then pick the FastEthernet interface that you want to configure (in the example below, we're selecting FastEthernet0/1).

6. Enter the following IPs on these interfaces:

  • FastEthernet0/1: 192.168.1.1

  • FastEthernet0/2: 192.168.2.1

  • FastEthernet0/3: 192.168.3.1

  • All subnet masks will be 255.255.255.0

Note that because each port is a distinct interface, they all have to be given their own address.

6. Once all of the interfaces are configured, try pinging PC1 and PC2 from PC0. If configured correctly, the pings should succeed!

  • Note that sometimes the first ping request between two machines will time out - this is just a relic of Packet Tracer, and subsequent pings should succeed.

Q1: SUBMIT screenshots of a successful ping between PC0 and PC1 (2 points) and a successful ping between PC0 and PC2 (2 points)

Part 2: Packet Tracer Simulation Mode

1. Click on the Simulation button in the bottom-right corner of the Packet Tracer window.

2. A Simulation panel will appear on the right side of the window. Since Packet Tracer will simulate many protocols by default, click the 'Show All/None' button at the bottom of this window, and then click the 'Edit Filters' button. Check the ICMP box in the IPv4 tab of the window that pops up.

Now, ping PC1 from PC0. The initial ping packet should appear in the simulation window. Click the '►|' button a few times until the packet reaches PC1 - you should see the following packets in the simulation window:

If you click on the packet at the Multilayer Switch, you'll receive a summary of the OSI information the packet contains as it both arrives at and leaves the switch. In particular, at layer 2 you'll see something like 'AAAA.AAAA.AAAA >> BBBB.BBBB.BBBB' - this indicates that the packet is being sent from the MAC address AAAA.AAAA.AAAA to the MAC address BBBB.BBBB.BBBB. If you click on the Inbound and Outbound detail tabs, you can see how this information is specifically formatted within each packet.

Q2: SUBMIT answers to the following questions:

  • What is the Source and Destination MAC address of the packet as it arrives at the switch? (1 point) SCREEN CAPTURE

  • What is the Source and Destination MAC address of the packet as it leaves the switch? (1 point) SCREEN CAPTURE

  • Why does the Destination MAC of the packet arriving at the switch match the Source MAC of the packet leaving the switch? (3 point)

Because this shows one device sending a packet to another device. And when the second device responds the sender and receiver mac addresses switch.

  • How do you set the gateway address on a workstation in Packet Tracer?

  • How do you set the IP and subnet mask on different interfaces of a multilayer switch?

  • How do you enter simulation mode in Packet Tracer?

  • How do you set which types of packets you want to see in Simulation Mode?

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