17.4.6 Lab – Test Network Latency with Ping and Traceroute Answers

 

Goals Part 1: Record network latency using Ping

          Part 2: Analyze Network Latency Using Traceroute

Context / Situation
This activity must be carried out on a live network in order to acquire accurate network latency information. Any local security prohibitions on using the ping command on the network should be confirmed with your Answers.
Answers Information: Some organisations turn off network-wide ICMP echo responses. Make sure there are no ICMP datagram-related local limitations before the students start this exercise. This activity requires that no local security policy restricts the use of ICMP datagrams.
This lab's goal is to assess network latency over time and at various times of the day in order to get a representative sample of normal network traffic. This will be achieved by using the ping command to examine the response latency from a remote computer. The average latency (mean) and the range (maximum and lowest) of the return delay times, measured in milliseconds, will be computed.

Resources Necessary
1 internet-connected computer
Instructions
Use Ping to Record Network Latency, Part 1
You will investigate the network latency of several websites worldwide in Part 1 of this article. In order to establish a performance baseline, this procedure may be employed in an enterprise production network.

First, check your connection.
To confirm the connection, ping the following Regional Internet Registry (RIR) websites:
Launch the command prompt
Pinging www.lacnic.net from C: Users: User1
Pinging www.afrinic.net from C: Users: User1
Pinging www.apnic.net from C: Users: User1
Note: The websites www.ripe.net and www.arin.net cannot be used for this lab since they do not respond to ICMP queries.
Resolving IPv4 addresses is possible with option -4 if the webpages are resolved to IPv6 addresses. The command is changed to www.arin.net ping -4.

Collect network data in step two.

Sending 25 echo queries to each address mentioned in Step 1 will provide enough data to calculate statistics on the ping result. Depending on your operating system, this step could need administrator rights. Create text files with the findings from each website.

To see the choices, enter ping at the command prompt.

ping C: UsersUser1

Use the following syntax: ping [-t] [-a] [-n count] [-l size] [-f] [-i TTL] [-v TOS]

[-r count, [-s count, [[-j host-list, [-k host-list]]]

Target name: [-w timeout] [-R] [-S srcaddr] [-4] [-6]

Options:

-tP till ceased pinging the designated host.

Type Control-Break to display statistics and continue.

Type Control-C to stop.

Resolve hostnames to addresses.

The number of echo requests to send: -n count.

sizeSend buffer size, -l.

Set the packet's "Don't Fragment" flag (IPv4-only).

TTLTime To Live

(IPv4-only. This parameter has been deprecated.) -v TOSType Of Service

omitted output

You may make 25 echo queries using the ping command with the count parameter, as shown below, and it will also create a text file with the name arin.txt in the current directory, which will have the replies to the echo requests.

ping www.lacnic.net -n 25 C:UsersUser1 > lacnic.txt

The output has been sent to a text file, lacnic.txt, in this example, and the > symbol is used to redirect the screen output to the file and overwrite the file if it already exists. If adding additional results to the file is needed, replace > with >> in the command.

To ping more websites, repeat the previous step.

ping -n 25 www.afrinic.net > afrinic.txt C:UsersUser1

ping -n 25 www.apnic.net > apnic.txt C:UsersUser1

Verify data gathering in step three.

Use the dir command to display the files in the directory to confirm that they have been produced. You can also use the wildcard * to filter solely for text files.

User1: dir *.txt in C:

OS volume is on drive C.

0A97-D265 is the volume serial number.

Directory of User1 at C: Users

Afrinic.txt, 02/07/2013 12:59 PM 1,642

01:615 PM on February 7, 2013 Apnic.txt

on July 2, 2013, 12:58 PM, 1,589 lacnic.txt

Use the more command at the command prompt to see the outcomes in the generated file.

more lacnic.txt at C: UsersUser1

sending a 32-byte ping to www.lacnic.net (200.3.14.184):

Message from 200.3.14.184: TTL=51 bytes=32 time=220ms

Message from 200.3.14.184: TTL=51 bytes=32 time=231ms

from 200.3.14.184 with response: bytes=32 time=243ms TTL=51

From 200.3.14.184: response with bytes 32, time 255, and TTL 51

Message from 200.3.14.184: TTL=51 bytes=32 time=266ms

omitted output

Message from 200.3.14.184: TTL=51 bytes=32 time=522ms

From 200.3.14.184: response with bytes 32, duration 195 ms, and TTL 51

From 200.3.14.184: response with bytes 32, time 207 ms, and TTL 51

From 200.3.14.184: response with bytes 32, time 219 ms, and TTL 51

Message from 200.3.14.184: TTL=51 bytes=32 time=232ms

Information about pings to 200.3.14.184:

packets: 25 were sent, 24 were received, 1 was lost (4% loss),

Round-trip times in milliseconds, roughly:

Minimum = 175 ms, Maximum = 522 ms, and Average = 253 ms.

Note: Press the Spacebar to see the remaining text in the file or Q to close it.

Enter your findings in the following table.

Analyze the delays' outcomes. What role does geography have in delay?

The response time is often longer than the actual travel distance to the destination.

Part 2: Document Network Latency Using Traceroute

Depending on the size of the ISPs and the locations of the source and destination hosts, the paths tracked may pass via several hops and ISPs. Network latency may be checked using the traceroute instructions. The route to the same locations as in Part 1 is traced using the tracert command in Part 2. The Windows equivalent of the traceroute command is tracert.

In order to trace the route, the tracert command employs ICMP TTL Exceed packets and ICMP echo responses.

Use the tracert command in Step 1 and save the results to text files.

To create the traceroute files, duplicate the instructions below:

C:UsersUser1> traceroute lacnic.txt www.lacnic.net

C:UsersUser1> traceroute afrinic.txt www.afrinic.net

Tracert www.apnic.net > traceroute apnic.txt in C:UsersUser1

Resolving to IPv4 addresses is possible with option -4 if the webpages are resolved to IPv6 addresses. Tracert www.lacnic.net > traceroute lacnic.txt becomes the command.

Step 2: Examine the traced route using the more command.

To see the contents of these files, use the more command:

more traceroute arin.txt in C:UsersUser1

Route tracking to www.lacnic.net [200.3.14 .184]

about 30 hops:

192.168.0.1 13 ms1 ms2

Request timed out at 2***.

ms173-219-1-12.suddenlink.net [173.219.1] 314 ms10 ms9 .12]

ms173-219-1-232.suddenlink.net [173.219.1] 439 ms38 ms45 .232]

ms173-219-1-98.suddenlink.net [173.219.1] 5*38 ms40 .98]

102.ear1.Chicago3.Level3.net 6*35 ms38 [4.28.58.177]

Request timed out at 7***.

GLOBAL-CROS.ear3.Miami2.Level3.net 880 ms79 ms77 [4.15.156.54]

168.197.23] 9341 ms221 ms222 mset-0-0-4-0.ptx-b.spo-piaf. Algar Telecom, Inc. .182]

Request timed out at 10***.

ms201-048-035-089.static.ctbctelecom.com.br [201.48.35] 11197 ms222 ms334 .89]

msxe-4-2-1-0.core1.nu.registro.br [200.160.0] 12225 ms175 ms176 .180]

Brazilian Registry Number: [200.160.0] 13269 ms222 ms221 msxe-0-0-0 .249]

msae0-0.gw1.jd.lacnic.net [200.160.0] 14217 ms228 ms218 .212]

15*281 ms220 ms200.3.12.34

www.lacnic.net 16231 ms233 ms212 [200.3.14.184]

The trace is finished.

In this instance, the default gateway responded in less than 1 millisecond (192.168.0.1). The round journey to 4.28.58.177 in hop count 6 took an average of 37 milliseconds. It took an average of 225 ms to go roundtrip to www.lacnic.net, the last stop.

The round trip time increased from an average of 78 ms to 298 ms between lines 8 and 9, indicating that there is higher network latency between these two lines.

Apply the exact same analysis to the remaining tracert findings.

What is the conclusion to be drawn about the link between the roundtrip time and location?

The response time is often longer than the actual travel distance to the destination.

Extended Traceroute in Part 3

Traceroute is implemented differently depending on the platform, however, all versions let the user choose how it behaves. The tracert command line in Windows has options and switches that may be used to do this.

Resolving an IP address to a domain name in reverse might cause a delay and provide unreliable tracert findings. The -d option should be added to the tracert command line to prevent the programme from attempting to reverse resolve hop IP addresses:

tracert -d at C: UsersUser1 traceroute d lacnic.txt> at www.lacnic.net

tracert -d www.afrinic.net > traceroute d afrinic.txt C:UsersUser1

tracert -d www.apnic.net > traceroute d apnic.txt C:UsersUser1

To see the contents of these files, use the more command:

more traceroute d lacnic.txt C: UsersUser1

Route tracking to www.lacnic.net [200.3.14 .184]

about 30 hops:

14 ms1, 1 ms1, and 192.168.0.1

Request timed out at 2***.

3*931 ms111 ms173.219.221.12

442, 41, 40, and 173.219.17.232

ms173.219.234.108 540 ms37 ms36

Request timed out at 6***.

Request timed out at 7***.

ms4.15.156.54 890 ms81 ms83

168.197.23.182, ms221 and ms223, and 9238

Request timed out at 10***.

ms246 ms224 ms201.48.35.89 11190

ms200.160.0.180 12227 ms222 ms222

13226 ms224, ms222, and ms200.160.0.249

ms200.160.0.212 14248 ms199 ms223

15180 ms, 270 ms, 224 ms, and 200.3.12.34

ms218 and ms223, and ms200.3.14.184

Trace is finished.

What has changed since the -d option was introduced to the tracert output?

IP addresses are not converted to hostnames by tracert -d.

Note: When Windows tracert is issued without any options, a list of possible options and their explanations will be shown.

Notably, the traceroute implementation in Cisco IOS supports fine adjustment but does not depend on command-line arguments. The administrator may enter values for the required parameters by answering a series of straightforward questions that the Cisco IOS extended traceroute displays.

Answers Note: Tracert output may be sent to a text file for data collecting and analysis, however doing so will prevent the learner from seeing how the command is executed. Encourage students to run tracert and tracert -d without sending the results to a text file. Tracert -d runs considerably faster than tracert since it doesn't need to determine IP addresses for the hops.

Questions for Thought

Important network latency information may be gleaned from the tracert and ping output. What should you do to get a precise baseline image of your network's network latency?

Answers will differ. Careful delay analysis must be done over many days and at various times during the day.

What applications are there for the baseline data?

If network response times have changed, you may check the baseline data against the most recent statistics. This study could help with network problems and arrange regular data transmission during off-peak times.