实验四

LAB 4 Cabling LANs and WANs

PART 1 Repeaters

Objective:

∙Create a simulated network topology

∙Apply IP addresses to workstations

∙Be familiar with the function of a repeater

∙Understand the Four Repeater Rule

∙Test the simulated topology

Step 1

Create the topology shown in the diagram in Packet Tracer. After connecting all the devices, assign each PC with a valid IP address and subnet mask. (You can use any IP addresses as long as they belong to the same network.)

Step 2

a) Click on the Simulation tab to start creating a scenario.

b) Add a packet and click on source PC 0 and then click on destination PC 1. Add another

packet from PC 1 to PC 2.

c) Click play to watch the simulation.

d) Take note of the time it takes for each packet to reach its destination. (Having more

repeaters between workstations adds latency to the packets.)

Step 3

a) Click once on the arrow on the left of the play button to go back one second (The

number in the Time box should be “6”)

b) Add a packet from PC 2 to PC 1.

c) Click on the Topology tab. Remove a connection then add another repeater anywhere

between Switch 0 and PC 2. Re-connect the devices.

d) Click on the Simulation and hit the play button to watch the simulation. (Latency results

in collision.)

PART 2 Repeaters and Hubs

Information:

1. This topology consists of 8 hosts along with 2 hubs and 1 repeater in the network.

Tips:

a) The Packet Tracer “i” located on the upper right of each page and device will give

information pertaining to that certain device or topology.

b) In simulation, the “i” nex t to the scenario drop down list will give information about the

specific scenario.

c) In simulation, clicking on the packets will show OSI layer information.

Procedures:

a) In the topology mode, add three (3) additional repeaters between the two (2) hubs.

b) In simulation mode, create a new scenario.

c) Send a packet from PC4 to PC0 and a packet from PC5 to PC1 at different times so that the

packets will not collide.

d) Before running the simulation, click on the individual packets on PC4 and PC5 to review the

packet and OSI information. Next, run the simulation.

e) After the first simulation, repeat step 3 except the packets does collide this time. Then

repeat step 4.

f) After the packets arrive to Hub1, click on the packet that leaves Hub1 and propagates to

Repeater0.

Questions:

a) What is the purpose of a hub and repeater in this network?