I run several Dahua IP cams and I am overall very satisfied with them. The biggest complaint I have is the video format when written to disk is a modified h264 format that won't play in standard players without conversion. You'll either need to use a special player or to convert the files to a standard mp4 with h264 video.
This works but it's not the fastest
ffmpeg -y -i input.dav -vcodec libx264 -crf 24 -filter:v "setpts=1*PTS" output.mp4
If you are OK with an AVI file then this command will be quick
ffmpeg -y -i input.dav -vcodec copy -movflags +faststart output.avi
For one of my runs I later wanted to add an additional camera but running another ethernet cable would be difficult. Instead I used the single cable and ran to a PoE extender and from the extender I ran two cams. I'm using the OdiySurveil 4-Port extender without issue.