Dahua NVR4108-P User Manual page 196

Here you can set a multiple cast group. Please refer to the following sheet for detailed information.

IP multiple cast group address
-224.0.0.0-239.255.255.255
-"D" address space
 The higher four-bit of the first byte="1110"

Reserved local multiple cast group address
-224.0.0.0-224.0.0.255
-TTL=1 When sending out telegraph
-For example
224.0.0.1 All systems in the sub-net
224.0.0.2 All routers in the sub-net
224.0.0.4 DVMRP router
224.0.0.5 OSPF router
224.0.0.13 PIMv2 router

Administrative scoped addressees
-239.0.0.0-239.255.255.255
-Private address space

Like the single broadcast address of RFC1918

Can not be used in Internet transmission

Used for multiple cast broadcast in limited space.
Except the above mentioned addresses of special meaning, you can use other addresses. For example:
Multiple cast IP: 235.8.8.36
Multiple cast PORT: 3666.
Figure 4-115
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