The traceroute command is the ideal tool
for finding where data is being sent in a network. The
traceroute command is similar to the ping
command, except that instead of testing end-to-end
connectivity, traceroute tests each step along the way.
This operation can be performed at either the user or
privileged EXEC levels. In this example, the path from York to
Rome is being traced. Along the way the path must go through
London and Paris. If one of these routers is unreachable, three
asterisks (*) will be returned instead of the name of the
router. The traceroute command will continue attempting
to reach the next step until the Ctrl-Shift-6 escape
sequence is used. A basic verification test also focuses on the
network layer. Use the show ip route command to
determine whether a routing table entry exists for the target
network. This command will be discussed in more detail in a
later module of this course. The procedure to use the
ping command is as follows: - ping IP address
or name of destination
- press the Enter
key
The procedure to use the traceroute
command is as follows: - traceroute IP address or
name of destination
- press the Enter key
Lab Activity Lab Exercise: Connectivity Tests –
Ping In this lab, the students will use the ping
command to send ICMP datagrams to a target host. Lab
Activity Lab Exercise: Connectivity Tests – Traceroute In
this lab, the student will use the traceroute command to
determine the path from a source to a destination. Lab
Activity e-Lab Activity: Alternate Connectivity Tests –
Ping In this lab, the students will use the ping
command to send ICMP datagrams to a target host and using the
information retrieved, accomplish the tasks.
Content
4.2 Getting Information about Remote Devices
4.2.6 Troubleshooting IP addressing issues
Addressing problems are the most common problems that occur on
IP networks. The following three commands are used to perform
address-related troubleshooting: - ping uses the
ICMP protocol to verify the hardware connection and the IP
address of the network layer. This is a basic testing
mechanism.
- telnet verifies the application
layer software between source and destination. This is the most
complete test mechanism available.
- traceroute
allows the location of failures in the path from the source to
the destination. Trace uses Time to Live values to generate
messages from each router along the path.
Lab
Activity Lab Exercise: Troubleshooting IP Address Issues In
this lab, the students will configure two routers and two
workstations in a small WAN.
Content Summary An
understanding of the following key points should have been
achieved: - Enabling and disabling CDP
- Using the
show cdp neighbors command
- Determining which
neighboring devices are connected to which local
interfaces
- Gathering network address information about
neighboring devices using CDP
- Establishing a Telnet
connection
- Verifying a Telnet connection
- Disconnecting from a Telnet session
- Suspending a
Telnet session
- Performing alternative connectivity
tests
- Troubleshooting remote terminal
connections