Question DVR screwing up my internet when connected to the router

[rank108]

Very weird situation

We have a couple cameras setup in our house for security and they're connected with an ethernet cable to the router so they can be accessed through the internet from the mobile app. After upgrading our internet speed the ISP provided a new 1gbps router (much better than the older one) but for some reason when I run any program/online game that requires internet on any pc/mobile it acts as if it's prevented by a firewall or that the internet is very slow to the point that it disconnects and connects endlessly even though the internet seems fine from the speed test (over 300mbps). As soon as I disconnect the DVR from the network everything goes back to normal.

Examples of programs/games:

PC
League of legends: The launcher opens and lets me login smoothly but as soon as I am in and press play it gives me that disconnect error as if I don't have internet even though I do (I can surf the web, watch netflix, etc..).

Steam:
Takes minutes to let me login and all the online games they either launch but very laggy with multiple disconnects and reconnects or they don't launch at all. Surprisingly, updating the games themselves from steam is fine.

TeamViewer: I can login into my account without any issues and once I choose a pc to connect to It lets me connect for around a minute then freezes forever.

Mobile:

TFT: Can't login, it acts as if I don't even have internet.

TeamViewer Mobile: After connecting to a remote pc for around a couple minutes it freezes and says that I don't have internet.



All of these issues are literally solved as soon as I unplug the DVR's ethernet cable from the router.
I tried checking if really it was a firewall issue but everything checks out. I also reset the DVR's software but it did nothing.

 

[bill001g]

Sounds like you have a duplicate IP address or the dvr is also running dhcp

 

[Ralston18]

Make and model router?

Make and model DVR?

Make and model cameras?

Have you assigned any static IPs addresses to any network device(s)?

Without the DVR plugged in, access the router's admin screens (you will need the login name and password) and look for some listing of connected network devices. The list may include connected devices and devices that were connected but are not currently found on the network.

Make note of devices, IP addresses, and MACs (Physical Addresses). A screen capture is a good way to do so.

Then plug the DVR in , wait a few minutes, and look again for any duplicate IP addresses or duplicate Physical Addresses. Capture the results.

Compare the results between without and with the DVR. Also look for any duplicate IP addresses or duplicate Physical Addresses.

Another way to look is to run "arp -a" (without quotes) via the Command Prompt on a connected network computer.

Without and without the DVR. Look for any duplicates.

As stated above you should not have any duplicate Internet Addresses