> 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-capture.md).

# Packet capture

![Packet Capture Center](https://1807546539-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FhgHCHWL3861o2DBW53aA%2Fuploads%2FNG8J8ai9LxCci1wUAhQO%2Fve20261112v5-tutorial-capture-center.png?alt=media)

GUI walkthrough for capturing packets on lab links. For link delay/loss see [Link inspector and impairment](/labs/link-inspector-and-impairment.md). For console steps see [Operate and consoles](/labs/operate-and-consoles.md).

## Goal

Start a capture on a link, watch it run, stop it, and download a PCAP - from the Capture Center or the in-lab Captures dock.

## Why Packet Capture exists

Consoles show control plane. Capture shows what actually crossed the wire so you can prove failover, ACL drops, or demo Wireshark without leaving VEX-NX.

## GUI tutorial

### Step 1 - Open Packet Capture Center

![Capture Center](https://1807546539-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FhgHCHWL3861o2DBW53aA%2Fuploads%2FNG8J8ai9LxCci1wUAhQO%2Fve20261112v5-tutorial-capture-center.png?alt=media)

1. Sidebar -> **Packet Capture** (route `/capture`)
2. Confirm you see the capture studio (labs / jobs list)

|                  |                                             |
| ---------------- | ------------------------------------------- |
| **What you see** | Capture Center workspace                    |
| **Expected**     | You can pick a lab and start or review jobs |

### Step 2 - Prefer in-lab Captures dock (same jobs)

![Captures dock ready](https://1807546539-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FhgHCHWL3861o2DBW53aA%2Fuploads%2Fw1cS9c6llMMtZyfQnXhg%2Fve20261112v5-tutorial-capture-start.png?alt=media)

1. Open the lab -> **Operate**
2. Select a **link** on the canvas (or a node with one link)
3. Click **Capture** / **Captures** on the toolbar or More menu
4. The bottom **Captures** dock opens (you stay in the lab - no forced navigation away)

|                  |                                                         |
| ---------------- | ------------------------------------------------------- |
| **What you see** | Captures dock with Start / filter                       |
| **Expected**     | Dock is ready; Start is enabled when a link is selected |

### Step 3 - Start capture

1. Optional: set a BPF-style filter if the UI offers one
2. Click **Start**
3. Wait for status **running**

![Capture running](https://1807546539-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FhgHCHWL3861o2DBW53aA%2Fuploads%2FpDX9KJYr82cL4UYFyQf9%2Fve20261112v5-tutorial-capture-running.png?alt=media)

|                  |                                       |
| ---------------- | ------------------------------------- |
| **What you see** | Running job in the Captures dock      |
| **Expected**     | Toast or status shows capture started |

### Step 4 - Generate traffic (so the PCAP is useful)

1. Open consoles on both ends ([Operate and consoles](/labs/operate-and-consoles.md))
2. Ping or run a small flow across the captured link
3. Or use Traffic Lens sample / live traffic ([Traffic Lens](/labs/traffic-lens.md))

### Step 5 - Stop and download

1. In the Captures dock, click **Stop**
2. Click **Download** for the PCAP
3. Open in Wireshark on your PC if needed

|                  |                                  |
| ---------------- | -------------------------------- |
| **What you see** | Stopped job with download action |
| **Expected**     | A `.pcap` file downloads         |

### Step 6 - Same capture from Link Inspector

1. Click the link -> open the link dock
2. Open the **Capture** tab
3. Start / Stop from there - same session model as the Captures dock

Details: [Link inspector and impairment](/labs/link-inspector-and-impairment.md).

## Expected result

* Capture jobs appear in the dock and Capture Center
* Download yields a PCAP you can open externally
* Stopping the lab does not replace explicit Stop on the job (always Stop before you leave)

## If it fails

* Start disabled -> select a link first (or a node that has exactly one link)
* Empty PCAP -> no traffic; ping across the path while capture runs
* 403 / missing -> edition or permission; check [Features](/getting-started/features.md)
* Looking for Capture Center mid-lab -> use the in-lab Captures dock; Center is for studio overview

## Related

* [Operate and consoles](/labs/operate-and-consoles.md)
* [Traffic Lens](/labs/traffic-lens.md)
* [Link inspector and impairment](/labs/link-inspector-and-impairment.md)
* Visual Feature Atlas - Operate


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