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Diagnostic Tools Overview
Juniper Networks devices support a suite of J-Web tools and CLI operational mode commands for evaluating system health and performance. Diagnostic tools and commands test the connectivity and reachability of hosts in the network.
Use the J-Web Diagnose options to diagnose a device. J-Web results appear in the browser.
Use CLI operational mode commands to diagnose a device. You can view the CLI command output on the console or management device. You can filter the output to a file.
To use the J-Web user interface and CLI operational tools, you must have the appropriate access privileges.
This section contains the following topics:
J-Web Diagnostic Tools
The J-Web diagnostic tools consist of the options that appear when you select Troubleshoot and Maintain in the task bar. Table 1 describes the functions of the Troubleshoot options.
Option |
Function |
|---|---|
| Troubleshoot Options | |
Ping Host |
Allows you to ping a remote host. You can configure advanced options for the ping operation. |
Ping MPLS |
Allows you to ping an MPLS endpoint using various options. |
Traceroute |
Allows you to trace a route between the device and a remote host. You can configure advanced options for the traceroute operation. |
Packet Capture |
Allows you to capture and analyze router control traffic. |
| Maintain Options | |
Files |
Allows you to manage log, temporary, and core files on the device. |
Upgrade |
Allows you to upgrade and manage Junos OS packages. |
Licenses |
Displays the summary of the licenses needed and used for each feature that requires a license. Allows you to add licenses. |
Reboot |
Allows you to reboot the device at a specified time. |
CLI Diagnostic Commands
The CLI commands available in operational mode allow you to perform the same monitoring, troubleshooting, and management tasks you can perform with the J-Web user interface. Instead of invoking the tools through a graphical interface, you use operational mode commands to perform the tasks.
CLI command output appears on the screen of your console or management device, or you
can filter the output to a file. For operational commands that display output, such
as the show commands, you can redirect the output into a filter or
a file. When you display help about these commands, one of the options listed is
|, called a pipe, which allows you to filter the command
output.
You can use the
mtrace command to display trace information about a multicast
path from a source to a
receiver.
To view a list of top-level operational mode commands, type a question mark (?) at the command-line prompt.
You can view CLI diagnostic commands at the top level of operational mode listed in Table 2.
Command |
Function |
|---|---|
| Controlling the CLI Environment | |
|
Configures the CLI display. |
| Diagnosis and Troubleshooting | |
|
Clears statistics and protocol database information. |
|
Traces information about multicast paths from source to receiver. |
|
Performs real-time debugging of various Junos OS components, including the routing protocols and interfaces. |
|
Determines the reachability of a remote network host. |
|
Determines the reachability of an MPLS endpoint using various options. |
|
Tests the configuration and application of policy filters and AS path regular expressions. |
|
Traces the route to a remote network host. |
| Connecting to Other Network Systems | |
|
Opens secure shell connections. |
|
Opens Telnet sessions to other hosts on the network. |
| Management | |
|
Copies files from one location on the device to another, from the device to a remote system, or from a remote system to the device. |
|
Restarts the various system processes, including the routing protocol, interface, and SNMP processes. |
|
Performs system-level operations, including stopping and rebooting the device and loading Junos OS images. |
|
Exits the CLI and starts a UNIX shell. |
|
Enters configuration mode. |
|
Exits the CLI and returns to the UNIX shell. |