Active and Candidate

Quiz: https://networkdirection.net/labsandquizzes/quizzes/juniper-jncia/active-and-candidate

Labs: https://networkdirection.net/labsandquizzes/labs/jncia-labs/active-and-candidate

Notes

Unlike some vendors, Juniper changes are not applied immediately. They need to be committed first.

The ‘active’ configuration is the configuration that’s running right now. The candidate config is a copy of the active that we’re making changes to. This overwrites the active configuration when it’s committed.

Candidate configs are stored in /var/rundb/juniper.data

When committing, Junos runs some checks to make sure the changes are fine before they’re applied. If they’re not fine, the commit will fail, and no changes are made.

‘Private configuration’ means that everyone in configuration mode will get their own copy of the candidate config. This stops admins making changes to each other’s configs. These may need to be synchronised before committing.

‘Exclusive configuration’ means that only one admin will be able to edit the configuration. This locks out other changes until the admin leaves exclusive mode.

Configuration archival takes backups of the config, and stores it on a remote server. This can be at regular intervals, or whenever changes are made.

These files are temporarily stored in /var/transfer/config. Archive sites can use either FTP or SCP.

The file naming convention is hostname.juniper.conf.gz_yyyymmdd_HHMMSS

Whenever a config is archived to a remote site, a syslog entry is raised.

Command Summary

Command	Mode	Description
commit	Configuration	Move a candidate config to the active config (applies configuration changes)
commit check	Configuration	Confirm your changes are valid, without committing them
commit comment	Configuration	Add a comment to the commit
commit at	Configuration	Schedule a commit
commit and-quit	Configuration	Commit, and take us back to operational mode
show | compare	Configuration	Compare your changes (candidate) to the active config
configure private	Operational	Enter private configuration mode
configure exclusive	Operational	Enter exclusive configuration mode
update	Configuration	Sync the candidate config with changes others have made
set system archival configuration archive-sites	Configuration	A site to archive the config to
set system archival configuration transfer-interval	Configuration	A regular interval to perform an archive
set system archival configuration transfer-on-commit	Configuration	Archive config when committing
test configuration FILE	Operational	Test if a configuration file is ok

Additional References

Configuration Files

https://www.juniper.net/documentation/en_US/junos/topics/concept/junos-configuration-files.html