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Etiquette Reminder
Chat rules and etiquette
While it is great to connect before class begins in the chat space and I encourage
that …
During class please only use the chat space for posting questions or trying to
answer a question (from myself or classmate) – I very much encourage that as it is
a great way to learn
• Otherwise questions get lost in the chatter and the incessant posting is a distraction
while talking/listening
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INFO-1280
Test Reminder:
The final grade is based on several assessments:
Theory Component (on campus)
Test #1 Monday October 7th 11am-1pm on-campus (10%)
• You will be assigned a room (TBD)
Test #2 Monday November 18th 11am-1pm on campus (20%)
• You will be assigned a room (TBD)
Final Exam Week 15 which is exam week (20%)
• Date/time TBD (to be determined)
Tests/exams are on campus, not online
Room booking will be posted when available
3
Michael McNorgan 2020
INFO-1280
Lab Assignment Reminder:
The final grade is based on several assessments:
Practical (in-class lab assignments) Component
Lab Assignment #1 (5%)
• Week of Sept. 23rd
Lab Assignment #2 (10%)
• Week of Oct. 14th
Lab Assignment #3 (15%)
• Week of Nov. 11th
Lab Assignment #4 (20%)
• Week of Dec. 2nd
The actual day/time is your regular lab day/time for that week.
This is not a take home assignment; it is completed in lab on the equipment.
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Michael McNorgan 2020
Module 13: ICMP
Introduction of Networks v7.0
(ITN)
Module Objectives
Module Title: ICMP
Module Objective: Use various tools to test network connectivity.
Topic Title Topic Objective
ICMP Messages Explain how ICMP is used to test network connectivity.
Ping and Traceroute Testing Use ping and traceroute utilities to test network connectivity.
© 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 6
13.1 ICMP Messages
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ICMP Messages
ICMPv4 and ICMPv6 Messages
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ICMP Messages
ICMPv4 and ICMPv6 Messages
• Internet Control Message Protocol (ICMP) provides feedback about issues related to the
processing of IP packets under certain conditions.
• The ICMP messages common to both ICMPv4 and ICMPv6 include:
• Host reachability
• Destination or Service Unreachable
• Time exceeded
Note: ICMPv4 messages are not required and are often not allowed within a network for
security reasons.
© 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 9
ICMP Messages
Host Reachability
ICMP Echo Message can be used to
test the reachability of a host on an IP
network.
How have you tested host reachability
this semester?
What are the two types of Echo
messages?
If a host does not reply to an Echo
message does that automatically mean
the destination host is down?
© 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 10
ICMP Messages
Destination or Service Unreachable
• An ICMP Destination Unreachable message can be used to notify the source that a
destination or service is unreachable.
A few Destination Unreachable A few Destination Unreachable codes for
codes for ICMPv4 are as follows: ICMPv6 are as follows:
• 0 - Net unreachable • 0 - No route to destination
• 1 - Host unreachable • 1 - Communication with the destination is
administratively prohibited (e.g., firewall)
• 2 - Protocol unreachable
• 2 – Beyond scope of the source address
• 3 - Port unreachable
• 3 - Address unreachable
• 4 - Port unreachable
© 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 11
ICMP Messages
Destination or Service Unreachable
• The output of a ping command may be vague, Wireshark can provide more specifics about
which code was returned.
© 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 12
ICMP Messages
Time Exceeded
• What is happening on your network based on the output from this command?
© 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 13
ICMP Messages
ICMPv6 Messages
ICMPv6 features four new protocols as part of the Neighbor Discovery Protocol (ND or NDP).
Messaging between an IPv6 router and an Messaging between IPv6 devices, including
IPv6 device, including dynamic address duplicate address detection and address
allocation are as follows: resolution are as follows:
• Router Solicitation (RS) message • Neighbor Solicitation (NS) message
• Router Advertisement (RA) message • Neighbor Advertisement (NA) message
© 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 14
ICMP Messages
ICMPv6 Messages (Cont.)
• RA messages send every 200 seconds by
IPv6 enabled router.
• What information is in an RA message?
• A host using Stateless Address
Autoconfiguration (SLAAC) will set its
default gateway to what?
© 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 15
ICMP Messages
ICMPv6 Messages (Cont.)
• For efficiency, what type of message does
client send to trigger router to send an RA?
• Discuss exchange between PC1 and R1.
© 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 16
ICMP Messages
ICMPv6 Messages (Cont.)
• A device assigned a global IPv6 unicast or
link-local unicast address, may perform
duplicate address detection to ensure that
the IPv6 address is unique, why?
• Suggest a way PC1 could perform this
detection by describing the message(s)
PC1 could create.
© 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 17
ICMP Messages
ICMPv6 Messages (Cont.)
• To determine the MAC address for the
destination, the device will send an NS
message.
• In the figure, R1 sends a NS message to
2001:db8:acad:1::10 asking for its MAC
address.
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13.2 Ping and Traceroute Tests
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Ping and Traceroute Tests
Ping – Test Connectivity
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Ping and Traceroute Tests
Ping the Loopback
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Ping and Traceroute Tests
Ping the Default Gateway
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Ping and Traceroute Tests
Ping a Remote Host
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Ping and Traceroute Tests
Traceroute – Test the Path
Discuss the traceroute or tracert utility
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Ping and Traceroute Tests
Traceroute – Test the Path (Cont.)
• The first message sent from traceroute will
have a TTL field value of 1. This causes the
TTL to time out at the first router. This router
then responds with a ICMPv4 Time
Exceeded message.
• Traceroute then progressively increments
the TTL field (2, 3, 4...) for each sequence
of messages. This provides the trace with
the address of each hop as the packets time
out further down the path.
• The TTL field continues to be increased until
the destination is reached, or it is
incremented to a predefined maximum.
© 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 25
INFO-1280
Test Reminder:
The final grade is based on several assessments:
Theory Component (on campus)
Test #1 Monday October 7th 11am-1pm on-campus (10%)
• You will be assigned a room (TBD)
Test #2 Monday November 18th 11am-1pm on campus (20%)
• You will be assigned a room (TBD)
Final Exam Week 15 which is exam week (20%)
• Date/time TBD (to be determined)
Tests/exams are on campus, not online
Room booking will be posted when available
32
Michael McNorgan 2020
INFO-1280
Lab Assignment Reminder:
The final grade is based on several assessments:
Practical (in-class lab assignments) Component
Lab Assignment #1 (5%)
• Week of Sept. 23rd
Lab Assignment #2 (10%)
• Week of Oct. 14th
Lab Assignment #3 (15%)
• Week of Nov. 11th
Lab Assignment #4 (20%)
• Week of Dec. 2nd
The actual day/time is your regular lab day/time for that week.
This is not a take home assignment; it is completed in lab on the equipment.
33
Michael McNorgan 2020
