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Observe and troubleshoot

Packet capture

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.

Packet Capture Center
Packet Capture Center

GUI walkthrough for capturing packets on lab links. For link delay/loss see Link inspector and impairment. For console steps see Operate and consoles.

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
Capture Center

  1. Sidebar -> Packet Capture (route /capture)
  2. Confirm you see the capture studio (labs / jobs list)
What you seeCapture Center workspace
ExpectedYou can pick a lab and start or review jobs

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

Captures dock ready
Captures dock ready

  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 seeCaptures dock with Start / filter
ExpectedDock 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
Capture running

What you seeRunning job in the Captures dock
ExpectedToast or status shows capture started

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

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

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 seeStopped job with download action
ExpectedA .pcap file downloads
  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.

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
  • Looking for Capture Center mid-lab -> use the in-lab Captures dock; Center is for studio overview