Use the J-Web Diagnose options to diagnose a device. J-Web results are displayed in the browser.
You can also diagnose the device with CLI operational mode commands. CLI command output appears on the screen of your console or management device, or you can filter the output to a file.
This section contains the following topics. To filter output to a file, see Filtering Command Output.
The J-Web diagnostic tools consist of the options that appear when you select Troubleshoot and Maintain in the task bar. Table 193 describes the functions of the Diagnose and Manage options.
Table 193: J-Web Interface Diagnose and Manage Options
Option |
Function |
---|---|
Troubleshoot Options | |
Ping Host |
Allows you to ping a remote host. You can configure advanced options for the ping operation. For details, see Using the J-Web Ping Host Tool. |
Ping MPLS |
Allows you to ping an MPLS endpoint using various options. For details, see MPLS Connection Checking. |
Traceroute |
Allows you to trace a route between the device and a remote host. You can configure advanced options for the traceroute operation. For details, see Tracing Unicast Routes from the J-Web Interface . |
Packet Capture |
Allows you to capture and analyze router control traffic. For details, see Capturing and Viewing Packets with the J-Web Interface. |
Maintain Options | |
Files |
Allows you manage log, temporary, and core files on the device. For details, see Managing Files with the J-Web Interface. |
Upgrade |
Allows you to upgrade and manage device software packages. For details, see Performing Software Upgrades and Reboots. |
Licenses |
Displays a summary of the licenses needed and used for each feature that requires a license. Allows you to add licenses. For details, see the JUNOS Software Administration Guide. |
Reboot |
Allows you to reboot the device at a specified time. For details, see Rebooting or Halting the Device with the J-Web Interface. |
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 interface. Instead of invoking the tools through a graphical interface, you use operational mode commands to perform the tasks.
Because the CLI is a superset of the J-Web interface, you can perform certain tasks only through the CLI. For example, you can use the mtrace command to display trace information about a multicast path from a source to a receiver, which is a feature available only through the CLI.
To view a list of top-level operational mode commands, type a question mark (?) at the command-line prompt.
At the top level of operational mode are the broad groups of CLI diagnostic commands listed in Table 194.
Table 194: CLI Diagnostic Command Summary
Command |
Function |
---|---|
Controlling the CLI Environment | |
set option |
Configures the CLI display. |
Diagnosis and Troubleshooting | |
clear |
Clears statistics and protocol database information. |
mtrace |
Traces information about multicast paths from source to receiver. For details, see Tracing Multicast Routes from the CLI. |
monitor |
Performs real-time debugging of various software components, including the routing protocols and interfaces. For details, see the following sections: |
ping |
Determines the reachability of a remote network host. For details, see Pinging Hosts from the CLI. |
ping mpls |
Determines the reachability of an MPLS endpoint using various options. For details, see MPLS Connection Checking. |
test |
Tests the configuration and application of policy filters and AS path regular expressions. |
traceroute |
Traces the route to a remote network host. For details, see Tracing Unicast Routes from the CLI. |
Connecting to Other Network Systems | |
ssh |
Opens secure shell connections. For details, see Using the ssh Command. |
telnet |
Opens Telnet sessions to other hosts on the network. For details, see Using the telnet Command. |
Management | |
copy |
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. |
restart option |
Restarts the various system processes, including the routing protocol, interface, and SNMP processes. |
request |
Performs system-level operations, including stopping and rebooting the device and loading software images. |
start |
Exits the CLI and starts a UNIX shell. |
configuration |
Enters configuration mode. For details, see the JUNOS Software Administration Guide. |
quit |
Exits the CLI and returns to the UNIX shell. |
Use either the J-Web ping MPLS diagnostic tool or the CLI ping mpls command to diagnose the state of label-switched paths (LSPs), Layer 2 and Layer 3 virtual private networks (VPNs), and Layer 2 circuits.
When you use the ping MPLS feature from a J Series device operating as the inbound (ingress) node at the entry point of an LSP or VPN, the router sends probe packets into the LSP or VPN. Based on how the LSP or VPN outbound (egress) node at the remote endpoint of the connection replies to the probes, you can determine the connectivity of the LSP or VPN.
Each probe is an echo request sent to the LSP or VPN exit point as an MPLS packet with a UDP payload. If the outbound node receives the echo request, it checks the contents of the probe and returns a value in the UDP payload of the response packet. If the J Series device receives the response packet, it reports a successful ping response.
Responses that take longer than 2 seconds are identified as failed probes.
Table 195 summarizes the options for using either the J-Web ping MPLS diagnostic tool or the CLI ping mpls command to display information about MPLS connections in VPNs and LSPs.
Table 195: Options for Checking MPLS Connections