a$.$ Click $172\mathrm{.}16\mathrm{.}31\mathrm{.}2$ and open the Command Prompt.

b$.$ Enter the arp $-$d command to clear the ARP table.

Close a command prompt

c$.$ Enter Simulation mode and enter the command ping $172\mathrm{.}16\mathrm{.}31\mathrm{.}3.$ Two PDUs will be generated. The ping command cannot complete the ICMP packet without knowing the MAC address of the destination. So the computer sends an ARP broadcast frame to find the MAC address of the destination.

d$.$ Click Capture$/$Forward once. The ARP PDU moves Switch$1$ while the ICMP PDU disappears, waiting for the ARP reply. Open the PDU and record the destination MAC address.

Question:

Is this address listed in the table above?

Type your answers here.

e$.$ Click Capture$/$Forward to move the PDU to the next device.

Question:

How many copies of the PDU did Switch$1$ make?

Type your answers here.

What is the IP address of the device that accepted the PDU?

Type your answers here.

f$.$ Open the PDU and examine Layer $2.$

Question:

What happened to the source and destination MAC addresses?

Type your answers here.

g$.$ Click Capture$/$Forward until the PDU returns to $172\mathrm{.}16\mathrm{.}31\mathrm{.}2.$

Question:

How many copies of the PDU did the switch make during the ARP reply?

Type your answers here.

Step $2$: Examine the ARP table.

a$.$ Note that the ICMP packet reappears. Open the PDU and examine the MAC addresses.

Question:

Do the MAC addresses of the source and destination align with their IP addresses?

Type your answers here.

b$.$ Switch back to Realtime and the ping completes.

c$.$ Click $172\mathrm{.}16\mathrm{.}31\mathrm{.}2$ and enter the arp $$a command.

Question:

To what IP address does the MAC address entry correspond?

Type your answers here.

In general, when does an end device issue an ARP request?

Type your answers here.

Part $2$: Examine a Switch MAC Address Table

Step $1$: Generate additional traffic to populate the switch MAC address table.

Open a command prompt

a$.$ From $172\mathrm{.}16\mathrm{.}31\mathrm{.}2,$ enter the ping $172\mathrm{.}16\mathrm{.}31\mathrm{.}4$ command.

b$.$ Click $10\mathrm{.}10\mathrm{.}10\mathrm{.}2$ and open the Command Prompt.

c$.$ Enter the ping $10\mathrm{.}10\mathrm{.}10\mathrm{.}3$ command.

Question:

How many replies were sent and received?

Type your answers here.

Close a command prompt

Step $2$: Examine the MAC address table on the switches.

a$.$ Click Switch$1$and then the CLI tab. Enter the show mac$-$address$-$table command.

Question:

Do the entries correspond to those in the table above?

Type your answers here.

b$.$ Click Switch$0,$ then the CLI tab. Enter the show mac$-$address$-$table command.

Questions:

Do the entries correspond to those in the table above?

Type your answers here.

Why are two MAC addresses associated with one port?

Type your answers here.

Part $3$: Examine the ARP Process in Remote Communications

Step $1$: Generate traffic to produce ARP traffic.

Open a command prompt

a$.$ Click $172\mathrm{.}16\mathrm{.}31\mathrm{.}2$ and open the Command Prompt.

b$.$ Enter the ping $10\mathrm{.}10\mathrm{.}10\mathrm{.}1$ command.

c$.$ Type arp $$a$.$

Question:

What is the IP address of the new ARP table entry?

Type your answers here.

d$.$ Enter arp $-$d to clear the ARP table and switch to Simulation mode.

e$.$ Repeat the ping to $10\mathrm{.}10\mathrm{.}10\mathrm{.}1.$

Question:

How many PDUs appear?

Type your answers here.

Close a command prompt

f$.$ Click Capture$/$Forward$.$ Click the PDU that is now at Switch$1.$

Question:

What is the target destination IP destination address of the ARP request?

Type your answers here.

g$.$ The destination IP address is not $10\mathrm{.}10\mathrm{.}10\mathrm{.}1.$

Question:

Why?

Type your answers here.

Step $2$: Examine the ARP table on Router$1.$

a$.$ Switch to Realtime mode. Click Router$1$ and then the CLI tab.

b$.$ Enter privileged EXEC mode and then the show mac$-$address$-$table command.

Question:

How many MAC addresses are in the table? Why?

Type your answers here.

c$.$ Enter the show arp command.

Questions:

Is there an entry for $172\mathrm{.}16\mathrm{.}31\mathrm{.}2?$

Type your answers here.

What happens to the first ping in a situation where the router responds to the ARP request?