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Remote captures

Feature availability
WARP modesZero Trust plans ↗
  • Gateway with WARP
  • Secure Web Gateway without DNS Filtering
All plans
SystemAvailabilityMinimum WARP version
Windows✅2024.12.492.0
macOS✅2024.12.492.0
Linux✅2024.12.492.0
iOS❌
Android❌
ChromeOS❌

Remote captures allow administrators to collect packet captures (PCAPs) and WARP diagnostic logs directly from end user devices. This data can be used to troubleshoot network problems, investigate security incidents, and identify performance bottlenecks.

Start a remote capture

Devices must be actively connected to the Internet for remote captures to run.

To capture data from a remote device:

  1. In Zero Trust ↗, go to DEX > Remote captures.
  2. Select up to 10 devices that you want to run a capture on. Devices must be registered in your Zero Trust organization.
  3. Configure the types of captures to run.
    • Packet captures (PCAP): Performs packet captures for traffic outside of the WARP tunnel (default network interface) and traffic inside of the WARP tunnel (WARP virtual interface).
    • WARP Diagnostics Logs: Generates a WARP diagnostic log of the past 96 hours. To include a routing test for all IPs and domains in your Split Tunnel configuration, select Test all routes.
  4. Select Run diagnostics.

DEX will now send capture requests to the configured devices. If the WARP client is disconnected, the capture will time out after 10 minutes.

Check remote capture status

To view a list of captures, go to DEX > Remote captures. The Status column displays one of the following options:

  • Success: The capture is complete and ready for download. Any partially successful captures will still upload to Cloudflare. For example, there could be a scenario where the PCAP succeeds on the primary network interface but fails on the WARP tunnel interface. You can review PCAP results to determine which PCAPs succeeded or failed.
  • Running: The capture is in progress on the device.
  • Pending Upload: The capture is complete but not yet ready for download.
  • Failed: The capture has either timed out or encountered an error. To retry the capture, check the WARP client version and connectivity status, then start a new capture.

Download remote captures

  1. In Zero Trust ↗, go to DEX > Remote captures.
  2. Find a successful capture.
  3. Select the three-dot menu and select Download.

This will download a ZIP file to your local machine called <capture-id>.zip. DEX will store capture data according to our log retention policy.

Device PCAP contents

The downloaded PCAP folder contains three files:

  • capture-default.pcap: Packet captures for the primary network interface.
  • capture-tunnel.pcap: Packet captures for traffic inside of the WARP tunnel.
  • results.json: Reports successful and failed packet captures.

You can analyze .pcap files using Wireshark or another third-party packet capture tool.

WARP Diag contents

Refer to WARP diagnostic logs for a description of each file.

WARP diagnostics analyzer (beta)

The WARP diagnostics analyzer highlights what Cloudflare determines to be the most important detection events in a warp-diag log. You can use the detection report to help parse your log files and identify the root cause of client issues. The WARP diagnostic analyzer is only available for logs collected via the dashboard.

To access the WARP diagnostic analyzer:

  1. In Zero Trust ↗, go to DEX > Remote captures.

  2. Locate an existing warp-diag log from the list or select Run diagnostics to generate a new warp-diag log.

  3. Select the three dots for the warp-diag log that you want to analyze, then select View WARP Diag.

    The Overview tab will display an AI-generated summary of the results, a list of detection events, and basic device information.

    Explanation of the fields
    FieldDescription
    Detection typeA common WARP issue that can appear in the diagnostic logs.
    OccurencesNumber of times an issue was detected in the logs.
    Severity levelIndicates the impact of the issue on WARP client functionality. The severity levels are:
    • Critical: Issue causes complete loss of functionality.
    • Warning: Issue causes degraded functionality but core features should still work.
    • No detection: Issue was not detected in the logs.
    Operating systemOS and OS version of the device.
    WARP versionWARP release version
    Profile IDWARP device profile UUID
    Service modeWARP mode
    Configuration nameName of the Zero Trust organization that WARP is connected to.
    Device IDID generated by the WARP client.

  4. Select a detection type for more information about the event and recommended next steps.

Cloudflare DEX will store the warp-diag log and its detection report per our log retention policy. To save a copy onto your local machine, download the log file and go to the JSON file tab to copy the report in JSON format.

Limitations

  • Packet captures are subject to the following limits:

    Limit TypeMaximum Value
    Time limit600 seconds
    File size50 MB
    Packet size1500 bytes

  • WARP diagnostic logs have no file size limit, but files larger than 100 MB cannot be uploaded to Cloudflare and must be shared directly with the admin.

  • Windows devices do not support concurrent remote captures. If you start a remote capture while another is in progress, the second capture will fail immediately.

  • PCAPs will fail on Windows if you have another third-party packet capture tool (such as, Packet Monitor pktmon) running.

  • On Windows, packet captures may fail on devices configured with a non-English language due to limitations with the underlying PktMon tool.