D-Link DCS-5211L User Manual page 59

Section 5 - Security
The Setup > Network page displays the port settings for your camera. If necessary, these ports can be changed if they are already in
use by other devices (e.g. in a multiple camera environment).
Note: Both the HTTP port and RTSP port are required to be opened for the DCS-5211L/DCS-5222L.
D-Link DCS-5211L/DCS-5222L User Manual 55