Troubleshooting the EX4600 Components
Understand Alarm Types and Severity Levels on EX Series Switches
This topic applies only to the J-Web Application package.
Alarms alert you to conditions that might prevent normal operation of the switch. Before monitoring alarms on a Juniper Networks EX Series Ethernet switch, become familiar with the terms defined in Table 1.
Table 1: Alarm Terms
Signal alerting you to conditions that might
prevent normal operation. On a switch, the alarm signal is the
Failure event that triggers an alarm.
Seriousness of the alarm. If the Alarm (
Preset alarm triggered by a physical condition on the switch such as a power supply failure, excessive component temperature, or media failure.
Preset alarm triggered by a missing rescue configuration or failure to install a license for a licensed software feature.
Note: On EX6200 switches, a system alarm can be triggered by an internal link error.
The switch supports these alarms:
Chassis alarms indicate a failure on the switch or one of its components. Chassis alarms are preset and cannot be modified.
System alarms indicate a missing rescue configuration. System alarms are preset and cannot be modified, although you can configure them to appear automatically in the J-Web interface display or the CLI display.
Alarm Severity Levels
Alarms on switches have two severity levels:
Major (red)—Indicates a critical situation on the switch that has resulted from one of the following conditions. A red alarm condition requires immediate action.
One or more hardware components have failed.
One or more hardware components have exceeded temperature thresholds.
An alarm condition configured on an interface has triggered a critical warning.
Minor (yellow or amber)—Indicates a noncritical condition on the switch that, if left unchecked, might cause an interruption in service or degradation in performance. A yellow or amber alarm condition requires monitoring or maintenance.
A missing rescue configuration generates a yellow or amber system alarm.
Interface Alarm Messages
Interface alarms are alarms that you configure to alert you when an interface is down.
To configure an interface link-down condition to trigger a red or yellow alarm, or to configure the link-down condition to be ignored, use the alarm statement at the [edit chassis] hierarchy level. You can specify the ethernet, fibre-channel, or management-ethernet interface type.
Fibre Channel alarms are valid only on QFX3500 devices.
When red alarms or major alarms are issued on QFX5100 and EX4600 switches, the alarm LED glows amber instead of red.
By default, major alarms are configured for interface link-down conditions on the control plane and management network interfaces in a QFabric system. The link-down alarms indicate that connectivity to the control plane network is down. You can configure these alarms to be ignored using the alarm statement at the [edit chassis] hierarchy level.
If you configure a yellow alarm on the QFX3008-I Interconnect device, it will be handled as a red alarm.
Creating an Emergency Boot Device
If Junos OS on the device is damaged in some way that prevents the software from loading properly, you can use an emergency boot device to repartition the primary disk and load a fresh installation of Junos OS. Use the following procedure to create an emergency boot device.
Before you begin, you need to download the installation media image for your device and Junos OS release from https://www.juniper.net/customers/support/ .
In the following procedure, we assume that you are creating the emergency boot device on a switch. You can create the emergency boot device on another Juniper Networks switch or router, or any PC or laptop that supports Linux. The steps you take to create the emergency boot device vary, depending on the device.
To create an emergency boot device:
- Use FTP to copy the installation media image into the
/var/tmpdirectory on the device.
- Insert a USB device into the USB port.
- From the Junos OS command-line interface (CLI), start
user@device> start shell
- Switch to the root account using the su command:
The password is the root password for the device. If you logged in to the device as root, you do not need to perform this step.
- Enter the following command on the device:
root@device% dd if=/var/tmp/filename of=/dev/da0 bs=1048576
The device writes the installation media image to the USB device:
root@device% dd if=/var/tmp/install-media-host-usb-ex-4e-flex-x86-64-18.3R1.10-secure.img 11006+1 records in 11006+1 records out 180332544 bytes transferred in 71.764266 secs (2512846 bytes/sec)
- Log out of the shell:
Performing a Recovery Installation
If Junos OS on your device is damaged in some way that prevents the software from loading correctly, you may need to perform a recovery installation using an emergency boot device (for example, a USB flash drive) to restore the default factory installation. Once you have recovered the software, you need to restore the device configuration. You can either create a new configuration as you did when the device was shipped from the factory, or if you saved the previous configuration, you can simply restore that file to the device.
If at all possible, you should try to perform the following steps before you perform the recovery installation:
Ensure that you have an emergency boot device to use during the installation. See Creating an Emergency Boot Device for information on how to create an emergency boot device.
Copy the existing configuration in the file
/config/juniper.conf.gzfrom the device to a remote system, such as a server, or to an emergency boot device. For extra safety, you can also copy the backup configurations (the files named
/config/juniper.conf.n, where n is a number from 0 through 9) to a remote system or to an emergency boot device.
The recovery installation process completely overwrites the entire contents of the internal flash storage.
Copy any other stored files to a remote system as desired.
To reinstall Junos OS:
Insert the emergency boot device into the device.
Power cycle the device.
The emergency boot device (external USB install media) is detected. At this time, you can load the Junos OS from the emergency boot device onto the internal flash storage.
The software prompts you with the following options:
Junos Snapshot Installer - (c) Juniper Networks 2013 Reboot Install Junos Snapshot [13.2-20131115_x_132_x51_vjunos.0Boot to host shell [debug]
Select Install Junos to format the internal flash storage and install the Junos OS on the emergency boot device onto the internal flash storage.
The device copies the software from the emergency boot device, occasionally displaying status messages. Copying the software can take up to 12 minutes.
When the software is finished being copied from the emergency device to the device, the device then reboots from the internal flash storage on which the software was just installed. When the reboot is complete, the device displays the Junos OS login prompt:
Create a new configuration as you did when the switch was shipped from the factory, or restore the previously saved configuration file to the device.
Remove the emergency boot device.