Activity 2 – IP Address. PING. ICMP.
Today we:
-
Build a basic network: 2 PCs and a switch
Configure the network
Test the connectivity
Simulate the PING command.
Exercise 1 – IP Addresses Allocation and PING
Build a simple network of 2 PCs interconnected via a 2950T switch. Connect PC0 to the interface
FastEthernet0/1 of the switch and PC1 to interface FastEthernet0/2. Rename PC1 to PC2 and PC0
to PC1.
You have installed a simple, physical network. Right now, the network is not “working”, in the sense that
we cannot send packets from one PC to the other. For that, you need to establish a connection between
the two PCs.
How to do that?
Step 1. PC1 Configuration:
1.1 Double click on PC1.
1.2 Click Desktop tab.
1.3 Click IP Configuration icon.
1.4 In the "IP Address" field, type: 192.168.10.1
1.5 In the "Subnet Mask" field, type: 255.255.255.0 (if not automatically generated).
1.6 Close the window.
Step 2. PC2 Configuration:
2.1 Double click on PC2.
2.2 Click Desktop tab.
2.3 Click IP Configuration icon.
2.4 In the IP Address field, type: 192.168.10.2
2.5 In the Subnet Mask field, type: 255.255.255.0 (if not automatically generated).
2.6 Close the window.
Or:
- Double click on PC2.
- Click Config tab.
- Click Interface tab, in the left side menu.
- Click FastEthernet0.
- In the IP Address field, type: 192.168.10.12
- In the Subnet Mask field, type: 255.255.255.0 (if not automatically generated).
- Close the window.
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Step 3. Connectivity test
In this moment, you have the network configured. Each PC has its own IP address. This means, each PC
can be identified in the Internet and can send/receive data. Now, you only need to test if your network
“works”, i.e. if the two PCs communicate with each other.
In order to test the connectivity, you need to send a message and see if you receive an
acknowledgement. We use the command PING for sending packets over the network:
3.1 Double click PC1 (in order to send packets from PC1 to PC2).
3.2 Click Desktop tab.
3.3 Double click on Command Prompt icon.
3.4 Type: ping 192.168.10.2
3.5 Hit Enter, and wait for a response.
A successful response is the following:
PC>ping 192.168.10.2
Pinging 192.168.10.2 with 32 bytes of data:
Reply from 192.168.10.2: bytes=32 time=170ms TTL=128
Reply from 192.168.10.2: bytes=32 time=71ms TTL=128
Reply from 192.168.10.2: bytes=32 time=70ms TTL=128
Reply from 192.168.10.2: bytes=32 time=68ms TTL=128
Ping statistics for 192.168.10.2:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 68ms, Maximum = 170ms, Average = 94ms
PING sends a response request by sending packets to a host and waits for echo response. PING
automatically sends packets, periodically, estimates the round-trip time of a packet in the network and
calculates the packet loss rate.
Try PING, from PC2 to PC1 as described in steps 3.1-3.5.
Exercise 2 – PING command simulation
In this exercise, you are going to experience the Simulation mode of Packet Tracer, by simulating the
PING command.
1. Enter Simulation mode by clicking Simulation Icon, in the bottom-right corner of the workspace.
2. Click Edit Filters button.
3. Check Show All/None to uncheck all filters, then check ICMP filter only.
The Internet Control Message Protocol (ICMP) is one of the main protocols of the Internet Protocol Suite.
It is used by network devices to send error messages indicating, for example, that a requested service is
not available or that a host could not be reached. The Internet Protocol Suite is a set of protocols used for
communication in Internet and similar networks.
Computer Networks Lab – Activity 2: IP Address. PING. ICMP.
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4. Try PING command from PC1 to PC2, as described in Exercise 1, Step 3 (3.1-3.5).
5. This time you are in Simulation mode. Observe the packets flow in the network and the relation
with PING’s response in Command Prompt.
Exercise 3
Build the network in this lab and try PINGing PCs. Give IPs at your choice.
Check the IP address of your computer. Is it static of dynamic?
Exercise 4 – IP Addressing (optional)
http://www.cabrillo.edu/~jgriffin/CIS192/files/resources/ipaddr.html
http://quizlet.com/5268567/ip-address-and-classes-exercise-flash-cards/
Computer Networks Lab – Activity 2: IP Address. PING. ICMP.