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