Run the lsof -i:8188 command. If the thttpd process is started, the following output is displayed:
Normal thttpd process
1. Connect an SSH tool to the NVR.
The default user name is root and default password is 123456.
2. Run the lsof -i:8188 to listen to the port.
If the thttpd process is abnormal, the status of 8188 is not LISTEN in the output that is displayed.
Abnormal thttpd process