An Overview of Junos Rescue and Recovery Options
When studying for the JNCIS-ENT certification, it's crucial to understand the various rescue and recovery options available in Junos. These options can be lifesavers when you're dealing with system failures or configuration issues. In this post, we'll delve into the different rescue and recovery options, including the rescue configuration, snapshot, and rollback features.
The rescue configuration is a known good configuration that you can revert to if you encounter issues with the current active configuration. This configuration is stored in a protected area of the file system and is not affected by system reboots or upgrades.
To save a rescue configuration, use the
request system configuration rescue save command. This command saves the current active configuration as the rescue configuration.
user@host> request system configuration rescue save
To revert to the rescue configuration, use the
rollback rescue command in configuration mode, and then commit the changes.
user@host# rollback rescue
A snapshot is a copy of the entire file system, including the Junos OS software and all configurations. You can use a snapshot to recover the system in case of a software failure.
To create a snapshot, use the
request system snapshot command. This command creates a snapshot and stores it in the alternate root partition.
user@host> request system snapshot
To recover the system using a snapshot, use the
request system reboot media internal command. This command reboots the system from the alternate root partition, which contains the snapshot.
user@host> request system reboot media internal
Junos OS automatically saves the last 50 configurations. You can rollback to any of these configurations using the
rollback command in configuration mode.
To display the list of saved configurations, use the
show system commit command.
user@host> show system commit
To rollback to a specific configuration, use the
rollback command followed by the configuration number.
user@host# rollback 1
In conclusion, Junos provides several rescue and recovery options that can help you recover from system failures or configuration issues. Understanding these options is not only crucial for real-world network engineering but also for passing the JNCIS-ENT certification exam. So, make sure to practice these commands and understand how they work.© Ben Jacobson.RSS