Turn off UDP broadcast

Brad

I just setup the Reolink Client on my server and I started having trouble with an RFID controller on my network. The RFID controller listens for UDP packets on port 2000 and acts on any commands in them, if they have invalid information/commands, it beeps an error code. After starting the Reolink Client, the RFID controller started beeping out error codes about every 5 seconds. I opened Wireshark to investigate, and I see my server sending out a broadcast UDP packet (to 255.255.255.255:2000) containing "aaaa0000" every 5 seconds, if I close the Reolink Client, the packets stop. I've tried unchecking the "Add device automatically" but the packets continue. Is there a way to disable this UDP Broadcast spamming?

carbonita

I'd be interested in hearing what the resolution for this is (and curious as to the purpose of the broadcast). A workaround might be to use http client for the cams.

Carl

Hi Brad, could you please submit your question to the support team? The R&D will answer your question. Refer to https://support.reolink.com/hc/en-us/requests/new.
Have a nice day!

Crimp On

When you get a resolution, please post an update here. I just used Wireshark to capture packets on my PC when I started the Reolink client software (Windows). Sure enough, there is a constant stream of UDP packets, in my case to 255.255.255.255 port 2018 (not 2000). I notice that the source port increments by one each time, although the destination port remains 2018.

Looks like it is hoping "somebody is listening" for a UDP broadcast and will respond with "I'm at IP address xx.xx.xx.xx" Maybe looking for a Reolink NVR?

Carl

Hi Crimp On, could you please submit your question to the support team? We need more details about this issue and the R&D will provide the solution for you soon. Refer to https://support.reolink.com/hc/en-us/requests/new.
Have a nice day!

Crimp On

Just to confirm what Brad reported: Reolink support confirms that yes, the Reolink client software searches for Reolink devices on the network by broadcasting UDP packets. Brad reported broadcasts with port 2000. My Wireshark capture seemed to indicate that the first broadcast was to port 2000 and the remaining broadcasts were to port 2018. (I did not keep it running very long.)

I know of no way to tell the client software not to search for devices.

This appears (to me) to be inconsistent with the whole process of "Add Device" and "Remove Device" (the trash can icon). Maybe the software searches for ANY device on the network that responds to UDP broadcasts on port (2000 or 2018), but it only displays the devices which have been "added". I guess the test would be to put a new Reolink camera on the network and see if the software finds it before it has been "added".

What did Brad learn from support?

Brad

The response from Reolink support:

Sorry to keep you waiting so long,
We confirmed with the R&D that this UDP broadcast is from the Reolink Client.
When you running the Reolink client, it will try to find the Reolink Devices on the LAN via that way.
It is normal and you needn't worry.

I then asked how to disable it because it was interfering with other devices on my network, and the reply was:

Sorry to tell you that for now, it cannot be disabled, but I will report your condition to our R&D department.
Sorry for the inconvenience caused.

I guess I have to find a way to block these UDP broadcasts without interfering with the software for the access control system, or find a different SDVR client.

Brad

Ok, I think I was able to block it using Windows firewall.
I created a "New Rule" and the settings I used were:

Rule Type = Custom
This Program path = "%Program Files% (x86)\Reolink Client\Reolink Client.exe"
Protocol type = UDP
Local Port = All Ports
Remote Port = Specific Ports & 2000
Which local IP addresses does this rule apply to? = Any IP address
Which remote IP addresses does this rule apply to? = These IP addresses: & 255.255.255.255
Action = Block the connection
When does this rule apply? = Domain, Private, & Public

After activating this rule, I am no longer seeing the UDP broadcast in wireshark (unless i disable the rule), my RFID controllers are no longer complaining, and the Reolink client still seems to be operating without issue (it doesn't seem to interfere with its core operation).

Thanks
-Brad