You can create a packet capture session for required hosts on the NSX Manager using the Packet Capture tool. After the packets are captured, the file is available to download. If your dashboard is indicating that a host is not in a healthy state, you can capture packets for that particular host for further troubleshooting.
For each session on the host, the packet capture file limit is 20 MB and the capture time limit is 10 minutes. A session remains active for 10 minutes or until the capture file reaches either 20 MB size or 20,000 packets, whichever limit is reached first. When any one of the limits is reached, the session is stopped. In the UI, you can create a maximum of 16 packet capture sessions. The NSX management plane limits the total captured file size across all sessions to 400 MB. When the combined packet file size of 400 MB is reached, a new capture session cannot be created. However, you can download the files of the previous packet capture sessions. If you want to start a new session after the limit of 400 MB file size is reached, you must clear the older sessions. An existing session is removed one hour after the session was created. If you restart NSX, all the existing sessions are cleared.
You cannot capture NSX VM interfaces.
You can perform the following tasks:
| Options | Description |
|---|---|
| NSX Manager | Select the NSX Manager for which you want to create a packet capture session. |
| CREATE SESSION | To start a new packet capture session, click CREATE SESSION. For details, see Create a Packet Capture Session. |
| STOP | Select the already started session, and click STOP. A confirmation dialog box appears. Click YES to stop the same session that is in-progress. |
| RESTART | Select the required session, and click RESTART. A confirmation dialog box appears. Click YES to restart the same session again. Restarting deletes the current session, clears the captured files, and starts a new session using the same configuration parameters. |
| CLEAR | Select the required session, and click CLEAR. A confirmation dialog box appears. Click YES to clear the session. |
| CLEAR ALL | If you want to clear all sessions, then click CLEAR ALL. A confirmation dialog box appears. Click YES to clear all the listed sessions. |
| DOWNLOAD | Select the required session, and click DOWNLOAD. You can also click the download icon. A confirmation dialog box appears. Click YES to download the captured session. |
You can view the number of active sessions and total file size. The session status can be as follows:
- Started: Wait for the session to finish.
- Error: To view the error details, click the link.
- Finished: After the session is finished, you can download the session. You can also restart, and clear the session.
- Stopped: The session that was forced stopped. You can restart, or clear the session.
