> For the complete documentation index, see [llms.txt](https://docs.vex-nx.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.vex-nx.com/labs/packet-journey-and-time-machine.md).

# Packet Journey and Time Machine

![Packet Journey](https://1807546539-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FhgHCHWL3861o2DBW53aA%2Fuploads%2Fh1aQW5MOogvyaUqmNnGY%2Fve20261112v5-packet-journey.png?alt=media)

![Time Machine](https://1807546539-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FhgHCHWL3861o2DBW53aA%2Fuploads%2FVIjFvD1yaL6L111OI3S5%2Fve20261112v5-time-machine.png?alt=media)

## Goal

Use Packet Journey to reason about modeled packet paths, and Time Machine / fault inject to rewind or stress a lab from the workspace.

## Packet Journey

### Open it

Open a lab -> workspace **More** -> **Packet Journey**.

### What it is

A modeled / inferred path view for teaching and design review. It is not a guarantee of live dataplane capture for every runtime. Prefer [Traffic Lens](/labs/traffic-lens.md) and [Packet capture](/labs/packet-capture.md) when you need live counters or PCAP evidence.

### Recipe

1. Build and Start a small topology
2. Open Packet Journey from More
3. Select source / destination (or follow the panel prompts)
4. Compare the painted path with Validate / protocol lenses

## Time Machine and fault inject

### Open it

Lab workspace **More** -> **Time Machine** (and fault-inject controls where the panel exposes them).

### What you get

| Capability         | Use it for                                                           |
| ------------------ | -------------------------------------------------------------------- |
| **Time Machine**   | Lab timeline / restore points for experiment rewind                  |
| **Fault inject**   | Controlled failures (link / node style chaos) for teaching break-fix |
| **Lab versioning** | Related lab history APIs / UI when exposed on the lab                |

Exact retention and chaos types depend on the appliance build. If a control is disabled, the UI should say unavailable - do not invent CLI workarounds in docs.

## Related

* [Traffic Lens](/labs/traffic-lens.md)
* [Link inspector and impairment](/labs/link-inspector-and-impairment.md)
* [Lab Preflight and Black Box](/labs/lab-preflight-and-black-box.md)
* [Features](/getting-started/features.md)


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