Some cameras are disconnecting

[Trucker1962]

I just bought a Dahua NVR OEM 4216-16P-4K to replace an 8 channels nvr of the same kind. I just switch the cameras over to the newer nvr 8 are PoE and 4 are el cheapo QSee wireless. Everything was working fine
but after 1 month I noticed one morning that 3 of the PoE cameras are disconnected and it's asking me the password. I did change the password on all cameras and these 3 are reset to default admin.
Once I re-enter my new password they go back online and all is fine.
The system was originally installed by a company in 2013 and it was port forwarded for access thru my 4G phone.
UpnP is disabled
and I don't know how to swith them on my vpn.
If I just change the cat6 I can't access them on my phone and the 4 QSee are not working probably because of the IP address being from my local router.
How can I handle the cameras disconnecting after 24 to 48 hours in another word NOT keeping the assigned password and reverting to the original admin.
BTW I have no idea as to what kind of cameras (the PoE)are because they were purchased and bought and installed thru a 3rd party

 

[alastairstevenson]

it was port forwarded for access thru my 4G phone.

OK, so the entire internet has access to the system.

How can I handle the cameras disconnecting after 24 to 48 hours in another word NOT keeping the assigned password and reverting to the original admin.

I'd speculate that they are being hacked / messed with by mischievous / malicious access from the internet.
One way to confirm that would be to shut down the port forwarding and see if the problem persists.

This very good advice is worth reading and implementing :

How to Secure Your Network (Don't Get Hacked!)

Many camera networks are unsecure, even those installed by professionals. This guide gives basic instruction in how to secure a camera network from the most common types of attacks. Perhaps the most important rule of securing a computer network is to not forward ports to unsecure services...

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