Which command do you use to display the messages seen during the last system boot?

A

The command used to display the messages seen during the last system boot in Junos OS is "show system boot-messages." Therefore, the correct answer is A.

The "show system boot-messages" command displays messages that were generated during the boot process, including hardware initialization and self-tests, software initialization and component loading, and any errors or warning messages that were generated during the boot process.

Here's an example of how to use the command:

yamlCopy code
root> show system boot-messages Mar  4 22:54:53  kernel: Copyright (c) 1996-2019 Juniper Networks, Inc. Mar  4 22:54:53  kernel: All rights reserved. Mar  4 22:54:53  kernel: Copyright (c) 1992-2019 FreeBSD Foundation. Mar  4 22:54:53  kernel: ... Mar  4 22:54:53  kernel: FreeBSD/SMP: Multiprocessor System Detected: 16 CPUs Mar  4 22:54:53  kernel: ... Mar  4 22:54:54  init: /bin/sh on /etc/rc.boot finished (pid 3300, exit status 0) Mar  4 22:54:54  init: /bin/sh on /etc/rc.boot finished (pid 3302, exit status 0) Mar  4 22:54:54  init: /bin/sh on /etc/rc.boot finished (pid 3304, exit status 0) Mar  4 22:54:54  init: /bin/sh on /etc/rc.boot finished (pid 3306, exit status 0) Mar  4 22:54:54  init: /bin/sh on /etc/rc.boot finished (pid 3308, exit status 0) 

In this example, the output displays messages generated during the boot process, such as kernel initialization and process startup messages. These messages can help identify any issues that occurred during the boot process, which can aid in troubleshooting.