Transcript CCNA 1 Module 11 TCP/IP Transport and Application

CCNA 2 v3.1 Module 8
TCP/IP Suite Error and
Control Messages
© 2004, Cisco Systems, Inc. All rights reserved.
1
Purpose of This PowerPoint
• This PowerPoint primarily consists of the Target
Indicators (TIs) of this module in CCNA version
3.1.
• It was created to give instructors a PowerPoint to
take and modify as their own.
• This PowerPoint is:
NOT a study guide for the module final assessment.
NOT a study guide for the CCNA certification exam.
• Please report any mistakes you find in this
PowerPoint by using the Academy Connection
Help link.
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2
To Locate Instructional Resource
Materials on Academy Connection:
• Go to the Community FTP Center to locate
materials created by the instructor community
• Go to the Tools section
• Go to the Alpha Preview section
• Go to the Community link under Resources
• See the resources available on the Class home
page for classes you are offering
• Search http://www.cisco.com
• Contact your parent academy!
© 2004, Cisco Systems, Inc. All rights reserved.
3
Objectives
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4
Internet Control Message Protocol
(ICMP)
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5
Error Reporting and Error Correction
• ICMP is an error-reporting protocol for IP.
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6
ICMP Message Delivery
• ICMP messages are encapsulated as data
in datagrams in the same way any other
data is delivered using IP.
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7
Unreachable Networks
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8
Ping
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9
Detecting Excessively Long Routes
• Whether the actual path includes too many hops
or a circular routing path exists, the packet will
eventually reach the end of its life, known as its
time-to-live (TTL).
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10
ICMP Message Types
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11
Destination Unreachable Message
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12
Code Values for Destination
Unreachable Messages
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13
TCP/IP Suite Control Messages
• Control messages are used to inform
hosts of conditions such as network
congestion or the existence of a better
gateway to a remote network.
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14
ICMP Redirect/Change Requests
The default gateway
of the host may
need to use a
redirect/change
request to inform
the host of the best
path to a certain
network.
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15
Clock Synchronization and Transit Time
Estimation
• The ICMP timestamp request message
allows a host to ask for the current time
according to the remote host.
• The remote host uses an ICMP timestamp
reply message to respond to the request.
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16
Address Mask Requirements
• When a network administrator uses the
process of subnetting to divide a major IP
address into multiple subnets, a new
subnet mask is created.
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17
Router Discovery Message
• When a host on the network boots, and
the host has not been manually
configured with a default gateway, it can
learn of available routers through the
process of router discovery.
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18
Router Solicitation Message
• A host generates an ICMP router
solicitation message in response to a
missing default gateway.
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19
Congestion and Flow Control
Messages
ICMP source-quench messages are
used to reduce the amount of data lost
from congestion.
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20
Summary
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