Electronics Engineering DepartmentEC573L1 – Data Communications

Experiment No. 2MAC Address and Address Resolution Protocol

I. Objective(s):The activity aims to have the students be able to identify the MAC address and discuss the operation of Address Resolution Protocol (ARP).

II. Intended Learning Outcomes (ILOs):The students shall be able to:

1. show the computer’s MAC address2. explain the structure, composition and characteristics of MAC address3. demonstrate the operation of Address Resolution Protocol in computer network4. show and explain the contents of the Switching Table

III. Discussion:

MAC Address

MAC address is the network address used in data-link layer (layer 2) and is assigned to every network adapter of all (layer 2) active devices in the network. It is also known as link address, hardware or physical address. MAC address is used in data/computer network for node to node communication.

It is composed of 48 bits and usually expressed in 12 hexadecimal digits. The 48-bit address has two parts, the first 24 bits/6 hexadecimal digits (left side) represents the Organizational Unique Identifier (OUI) which is the same for adapters of the same manufacturer, the second 24 bits/6 hexadecimal digits (right side) is the manufacturer’s assigned and represents the serial number. Each MAC address is unique, that is, there is no instance that two devices have the same.

MAC address is written in any of following formats:

A1:34:98:DF:5C:B7A134.98DF.5CB7A1-34-98-DF-5C:-B7A1.34.98.DF.5C.B7

Address Resolution Protocol

The ARP protocol is one of the auxiliary protocols defined in the network layer. It belongs to the network layer and it maps an IP address to a MAC address. ARP accepts an IP address from the IP protocol, maps the address to the corresponding MAC address, and passes it to the data-link layer.

Anytime a host or a router needs to find the link-layer address of another host or router in its network, it sends an ARP request packet. The packet includes the link-layer and IP addresses of the sender and the IP address of the receiver. Because the sender does not know the link-layer address of the receiver, the query is broadcast over the link using the link-layer broadcast address. Every host or router on the network receives and processes the ARP request packet, but only the intended recipient recognizes its IP address and sends back an ARP response packet. The response packet contains the recipient's IP and link-layer addresses. The packet is unicast directly to the node that sent the request packet.

The arp command is used as a tool for confirming that a computer is successfully resolving network IP addresses to MAC addresses. The TCP/IP network protocol relies on IP addresses like 192.168.14.211 to identify individual devices and to assist in navigating data packets between networks. While the IP address is essential to move data from one LAN to another, it cannot deliver the data in the destination LAN by itself. It uses the MAC address to identify local devices and deliver

1

Electronics Engineering DepartmentEC573L1 – Data Communications

all data.

ARP maintains a table in the computer of IP and MAC address combinations. In other words, it keeps track of which MAC address is associated with an IP address. If ARP does not know the MAC address of a local device, it issues a broadcast using the IP address. This broadcast searches for the MAC address that corresponds to the IP address. If the IP address is active on the LAN, it will send a reply from which ARP will extract the MAC address. ARP will then add the address combination to the local ARP table of the requesting computer.

IV. Resources:

1. Windows OS Personal Computer (PC) preferably a Laptop w/ Network Interface Card (NIC)2. Link-Layer Switch3. Straight through Cable (at least one per group)

V. Procedure: After every numbered procedure, Go to the numbered Data and Results

1. Connect the PC to LAN switch with the Straight Through cable.

2. The Instructor will assign the management IP address of the LAN Switch

3. Set the following IP address accordingly in the PCa. Group 1/PC1: IP Address – 192.168.0.2, Subnet Mask – 255.255.255.0b. Group 2/PC2: IP Address – 192.168.0.3, Subnet Mask – 255.255.255.0c. Group 3/PC3: IP Address – 192.168.0.4, Subnet Mask – 255.255.255.0d. Group 4/PC4: IP Address – 192.168.0.5, Subnet Mask – 255.255.255.0e. Group 5/PC5: IP Address – 192.168.0.6, Subnet Mask – 255.255.255.0f. Group 6/PC6: IP Address – 192.168.0.7, Subnet Mask – 255.255.255.0

4. Open command prompt c:\> and type ipconfig <enter>. Record the result particularly the displayed information for the NIC in use (you may take a snapshot image).

5. Type ipconfig/all <enter>. Record the result particularly the displayed information for the NIC in use (you may take a snapshot image).

6. Type arp –a IP address <enter>. Do this for each of PCs’ IP address including your own.

Ex.: To view the ARP record for PC2: c:\>arp –a 192.168.1.2 <enter>

Record the resulting displayed information (you may take a snapshot image).

7. Type ping IP address <enter>. Do this for each of PCs’ IP address including your own.

Ex.: To ping PC2: c:\>ping 192.168.1.2 <enter>

A reply should be received.

8. Repeat procedure no. 6.

9. View the MAC address table of the LAN Switch (the Instructor will guide on how to view the MAC address table of the Switch). Record the pertinent information (you may take a snapshot image).

Course: EC 573L1 Experiment No.: 2Name: Mabaga, Argel Linard F. Section: EC51FC2

Date Performed: 08/03/15VI. Data and Results:

1. Show the information recorded in procedure no.4.

2

Electronics Engineering DepartmentEC573L1 – Data Communications

2. Describe the gathered information/data.

-The gathered information or data in the ipconfig command are TCP/IP network configuration values and refreshes Dynamic Host Configuration Protocol (DHCP) and Domain Name System (DNS) settings.

3. Show the information recorded in procedure no.5.

3

Electronics Engineering DepartmentEC573L1 – Data Communications

4. Describe the gathered information/data and the difference compared to procedure no. 4.

-Compare to ipconfig the ipconfig/all displays the full TCP/IP configuration for all adapters. Without this parameter, ipconfig displays only the IP address, subnet mask, and default gateway values for each adapter. Adapters can represent physical interfaces, such as installed network adapters, or logical interfaces, such as dial-up connections.

5. Show the information recorded in procedure no.6.

4

Electronics Engineering DepartmentEC573L1 – Data Communications

6. Describe the gathered information/data.

- The gathered data or information is the current ARP cache tables for all interfaces. ARP is a dynamic resolution protocol, which means that every resolution requires the interchange of messages on the network.

7. Show the information recorded in procedure no.8.

5

Electronics Engineering DepartmentEC573L1 – Data Communications

8. Describe the gathered information/data and the difference compared to procedure no. 6.

- The gathered data or information is the current ARP cache tables for all interfaces. ARP is a dynamic resolution protocol, which means that every resolution requires the interchange of messages on the network.

9. Show the information recorded in procedure no.9. Describe the gathered information/data.

6

Electronics Engineering DepartmentEC573L1 – Data Communications

- The gathered information or data shows the MAC address and the port number of the computers that is connected to the switch.

VII. Observation

7

Electronics Engineering DepartmentEC573L1 – Data Communications

Before using the command arp you must use the command ping first to know if the IP address is accessible.

You can view the status of your switch by typing its IP address in any web browser and you can also see its active ports.

Every device has its own IP and MAC address.

VIII. Conclusion Command prompt is a very helpful tool, you can see here the MAC address of other computers

that is connected to the switch by typing some commands ARP is so very helpful; it helps you to communicate in any device on your network by using it as a

link to IP address to the MAC address. MAC address is the unique identification of your computer. Ipconfig/all helps you to know your computer’s MAC address

IX. Recommendation

You need to turn the telnet client in order to see the mac address table You need to turn off your windows firewall in order to allow to connect to other computer Use a good UTP cable in order to have a better connection.

8

Electronics Engineering DepartmentEC573L1 – Data Communications

X. Assessment

CRITERIA BEGINNER1

ACCEPTABLE

2

PROFICIENT3 SCORE

I. Laboratory Skills

Manipulative SkillsMembers do not demonstrate needed skills.

Members occasionally demonstrate needed skills

Members always demonstrate needed skills.

Experimental Set-up

Members are unable to set-up the materials.

Members are able to set-up the materials with supervision.

Members are able to set-up the material with minimum supervision.

Process SkillsMembers do not demonstrate targeted process skills.

Members occasionally demonstrate targeted process skills.

Members always demonstrate targeted process skills.

Safety Precautions Members do not follow safety precautions.

Members follow safety precautions most of the time.

Members follow safety precautions at all times.

II. Work Habits Time Management / Members do not finish Members Members finish ahead of

9

Electronics Engineering DepartmentEC573L1 – Data Communications

Conduct of Experiment on time with incomplete

data.

finish on time with incomplete data.

time with complete data and time to revise data.

Cooperative and Teamwork

Members do not know their tasks and have no defined responsibilities. Group conflicts have to be settled by the teacher.

Members have defined responsibilities most of the time. Group conflicts are cooperatively managed most of the time.

Members are on tasks and have defined responsibilities at all times. Group conflicts are cooperatively managed at all times.

Neatness and Orderliness

Messy workplace during and after the experiment.

Clean and orderly workplace with occasional mess during and after the experiment.

Clean and orderly workplace at all times during and after the experiment.

Ability to do independent work

Members require supervision by the teacher.

Members require occasional supervision by the teacher.

Members do not need to be supervised by the teacher.

Other Comments/Observations: Total Score

Rating=(Total Score)

24×100

XI. Reference(s):B.A. Forouzan, Data Communications and Networking, 5th Edition, McGraw Hill, 2013http://highered.mcgraw-hill.com/sites/0073376221/student_view0/lab_assignments.html

10