Active and Candidate

Active and Candidate




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/

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

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

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