Boot Sequence

Table 1. Linux kernel version product support

Feature

Product

Release introduced

Linux kernel version

5320 Series

5.4 as of Fabric Engine 8.6

5420 Series

5.4 as of Fabric Engine 8.6

5520 Series

5.4 as of Fabric Engine 8.6

The switch goes through a boot sequence before it becomes fully operational. After you turn on power to the switch, the system starts.

The boot sequence consists of the following stages:

Note

Note

Extreme Networks offers universal hardware products that support more than one Network Operating System (NOS) personality. The first time you start a universal hardware product, the boot sequence can be different from what is documented in this section. The boot sequence documented in this section assumes a NOS selection of Fabric Engine is already established. For more information on NOS personalities, see Network Operating System Personalities.

The following figure shows a summary of the boot sequence.

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Boot Sequence
The boot sequence flowchart. First steps include powering the switch, initializing CPU and memory, loading Linux, and determining and loading the primary release. The switch looks for valid primary and backup configuration files to load. If neither exist, the switch uses a factory-default configuration or Zero Touch Deployment, depending on which the hardware supports. The final stage sends configuration information to the I/O process to begin operations.

Loading Linux

Depending on the Linux kernel used, the boot image is stored either in a boot flash partition, Secure Digital (SD), or Solid State Drive (SSD) flash card. The boot image includes the boot loader, and the Linux kernel and applications.

The boot location contains two versions of the boot image: a committed version (the primary release) and a backup version. A committed version is one that is marked as good (if you can start the system using that version). The system automatically uses the backup version if the system fails the first time you start with a new version.

Loading the Primary Release

You can store up to six software releases on the 5520 Series. If you have six releases already stored on the switch, you are prompted to remove one release before you can proceed to add and activate a new software release. You can store a maximum of two software releases on the 5320 Series and 5420 Series. If you attempt to add a third software release, the software displays a confirmation to overwrite the non-primary release. You can also use the software add <filename> -y to bypass the confirmation question and automatically overwrite the non-primary release.

The system saves software image files to the /intflash/release/ directory.

After loading the primary release, the CPU and basic system devices, such as the console port, initializes. At this stage, the I/O ports are not available; the system does not initialize the I/O ports until the port sends configuration data.

Deploying Zero Touch

Important

Important

Zero Touch Deployment does not function if primary or secondary configuration files exist.

After the system loads the primary release and the switch is in a Zero Touch Deployment-ready configuration mode, the switch automatically deploys without intervention.

For more information, see Zero Touch Deployment.

Loading the Configuration File

After the system loads the primary release, it identifies the location and file name of the primary configuration file. You can save this file in internal flash.

If the primary configuration file does not exist, the system looks for the backup configuration file, as identified by version.cfg. If this file does not exist, the system initiates Zero Touch functionality on the switch that enables Zero Touch Fabric Configuration. For more information, see Zero Touch Fabric Configuration.

The switch configuration consists of higher-level functionality, including:

The default switch configuration in Zero Touch Fabric Configuration mode includes the following:

The default switch configuration in factory default mode includes the following:

Configuration File Statements

In the configuration file, statements preceded by both the number sign (#) and exclamation point (!) load prior to the general configuration parameters. Statements preceded by only the number sign are comments meant to add clarity to the configuration; they do not load configuration parameters. The following table illustrates the difference between these two statement formats.

Table 2. Configuration file statements

Sample statement

Action

# software version : 8.6.0.0

Adds clarity to the configuration by identifying the software version.

#!no boot config flags sshd

Configures the flag to the false condition, prior to loading the general configuration.

Boot Sequence Modification

You can change the boot sequence in the following ways:

Runtime

After the switch is operational, you can use the runtime commands to perform configuration and management functions necessary to manage the system. These functions include the following

To access the runtime environment you need a connection from a PC or terminal to the switch. You can use a direct connection to the switch through the console port or remotely through Telnet or Secure Shell (SSH) sessions.

Important

Important

Before you attempt to access the switch using one of the preceding methods, ensure you first enable the corresponding daemon flags.