|
IP is limited because it is a
best effort delivery system. It has no mechanism to ensure that
the data is delivered, regardless of the problems it may encounter
on the network. Data may fail to reach its destination for a
variety of reasons, such as hardware failure, improper
configuration or incorrect routing information. To help identify
these failures, IP uses the Internet Control Message Protocol (ICMP)
to notify the sender of the data that there was an error in the
delivery process. This module describes the various types of ICMP
error messages and some of the ways they are used.
Because IP does not have a built-in
mechanism for sending error and control messages, it uses the ICMP
to send and receive error and control messages to hosts on a
network. This module focuses on control messages, which are
messages that provide information or configuration parameters to
hosts. Knowledge of ICMP control messages is an essential part of
network troubleshooting and is a key to a full understanding of IP
networks.
Students completing this module should be able to:
- Describe ICMP
- Describe the ICMP message format
- Identify ICMP error message
types
- Identify potential causes of
specific ICMP error messages
- Describe ICMP control messages
- Identify a variety of ICMP
control messages used in networks today
- Determine the causes for ICMP
control messages
|
