# Versions and diff

See exactly what changed between two versions, of the same device or of different devices (for example, to compare two switches that should be identical).

Source: https://docs.opennccm.com/en/equipos/versiones/

Video: 4.2 Versiones y comparación (https://youtu.be/gjrH7w1aOb4) · 4.1 Respaldos manuales y automáticos (https://youtu.be/gdB5zO9friA)

## How it works

1.  OpenNCCM connects to the device with its credential and runs the profile's backup command (e.g. `show running-config`, `display current-configuration`, `show configuration | display set`).
2.  It removes volatile lines (timestamps, checksums) so it does not record false changes.
3.  If the content changed since the last version, it saves a new encrypted version, with its SHA-256 fingerprint and the lines added and removed.
4.  If the profile supports it, it also backs up the startup configuration and compares both (startup/running conflict).
5.  It updates the inventory (model, serial, version), compares with the baseline and runs the compliance audit.

Each version records its **source**: `manual` (button), `scheduled` (task), `syslog` (detected in real time) or `push` (applied by OpenNCCM).

## View a version

On the device page, **Versions** tab, the **›** arrow on each version opens it in a side panel. From there you can **download**, **compare with the previous one**, **tag** it (for example "before migration"), **mark it as baseline** or **roll the device back to that version**.

On a **MikroTik RouterOS** device, the page's **…** menu also offers **Download .rsc (latest backup)**, the saved `/export` ready for `/import`, and **Download the device's .backup…**. The router creates the latter on the spot (`/system backup save`), OpenNCCM fetches it over SFTP and deletes it from the device. You can set a password to encrypt it. The .backup includes users and passwords and can only be restored on the same model; to move the configuration to another device, use the .rsc. The credential's user needs the *ftp* policy (SFTP).

*[Image: A version with its actions.]*

:::tip[Retention]
In Settings you can limit how many versions are kept per device. Tagged versions (including the baseline) are never deleted.
:::

## Configuration comparison

### How to use it

1.  In the device's **Versions** tab, click two versions on the timeline (the older one becomes A and the other B): the comparison appears beside it, in **side-by-side** or **unified** view.
2.  **Compare configurations** (from Search configs or the device's ⋯ menu) compares versions of different devices and lets you change the context (0, 3, 10 lines or the whole file) and swap A and B.

At the top, **What changed** sums up the differences in words (for example "in 'interface Gi0/1', 'shutdown' was added"). The **side-by-side** view shows version A on the left and B on the right, with line numbers: in red what was removed or modified, in green what was added or modified. The **unified** view shows the classic diff format. The **n** and **p** keys jump to the next or previous change, and the thin bar on the right marks where all of them are.

*[Image: Version timeline with A and B selected.]*

*[Image: Side-by-side comparison.]*

*[Image: Unified comparison.]*