Cisco CCNA 2 Instructor Manual page 101

Module 8 Summary
Before students begin Module 9, they should know where to look for many of the error
messages they may encounter.
Online assessment options include the end-of-module online quiz in the curriculum and the
online Module 8 exam. This is a very descriptive module so vocabulary or scenario-based
quizzes may be the preferred form of assessment.
Students should understand the following main points:
•
IP is a best-effort delivery method that uses ICMP messages to alert the sender
that the data did not reach its destination.
•
ICMP echo request and echo reply messages allow the network administrator to
test IP connectivity to aid in the troubleshooting process.
•
ICMP messages are transmitted with the IP protocol so their delivery is unreliable.
•
ICMP packets have their own special header information, which starts with a type
field and a code field.
•
Potential causes of specific ICMP error messages
•
The functions of ICMP control messages
•
ICMP redirect/change request messages
•
ICMP clock synchronization and transit time estimation messages
•
ICMP information request and reply messages
•
ICMP address mask request and reply messages
•
ICMP router discovery message
•
ICMP router solicitation message
•
ICMP congestion and flow control messages
100 - 238 CCNA 2: Routers and Routing Basics v3.1 Instructor Guide – Module 8
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