Configuration Rollback
Notes
It can sometimes be risky making changes, as mistakes can kick us out of the device. If we use commit confirmed, we can automatically roll back if we don’t confirm the changes.
Changes are confirmed by running another commit.
The default time before rollback is 10 minutes, but this can be changed on a case-by-case basis.
When changes are committed, a backup of the previous active config is placed in /config. The most recent backup is juniper.conf.gz.
Older backups are incremented from there. For example, juniper.conf.1.gz.
/config is on fast storage. A maximum of five backups are kept there. As they’re shuffled down, the oldest backups are moved to /var/db/config (or /config/db/config). This is slower storage, and can contain an additional 45 backups.
From configuration mode, we can roll back to any of these backups. Rollbacks go into the candidate config. Once this is done we still need to commit.
If we want, we can compare the candidate to the active config, to see the changes.
Command Summary
| Command | Mode | Description |
|---|---|---|
| commit confirmed | Configuration | Commit changes, but roll back if the changes aren’t confirmed |
| rollback | Configuration | Rolls back to a backup config (in configuration mode) |
| show | compare rollback | Configuration | Compares the current candidate to a backup (rollback point) |
| save | Either | Saves content to disk |
| file list | Operational | show files in a directory |
| file show | Operational | Show the contents of a file |
| file compare files FILE1 FILE2 | Operational | Compare the contents of two files |