BD Win7 blocking "multicast discover", but allows "broadcast discover"
I've recently bought a Silicon Dust HDHomeRun Flex-4K network tuner, to provide OTA/ATSC broadcast TV support for both ATSC 1.0 and ATSC 3.0 channels. The product includes DVR software functionality, with the HDHR DVR "server" service program running on either Win7 or Win10.
In support of this, HDHR "client" apps are available for smart devices, streaming devices, smart phones, etc. These client apps are available for (Android) NVidia Shield, (iOS) ATV4K, (Android) Samsung phones, (WebOS) LG OLED TV's, etc. So the "server" and any number of "clients" all exist on my home LAN, and work together as a whole-home DVR system allowing playing of live/recorded content via the Flex-4K tuners which is also network-based.
When the client apps launch they issue a "discover" command over the network, attempting to connect with the DVR server at whatever IP address it exists as. All but one of the client apps use a "broadcast discover" technique, which is absolutely not a problem for BitDefender. So all of these client apps have 100% success in connecting with the DVR server program running on the Win7/Win10 PC.
However one client app, namely the WebOS one that runs on the LG OLED TV, uses a "multicast discover" technique to reach the DVR server. I don't know why Silicon Dust programmed it that way but they did. And, unfortunately, there is some kind of blockage occurring in BitDefender for this type of request BUT ONLY IN WIN7! When the DVR server PC is booted to Win10, BitDefender running in that Win10 environment DOES NOT BLOCK THE "MULTICAST DISCOVER" and the LG app IS able to connect with the DVR server (again, running in Win10).
I've compared the BitDefender setups for both Win7 and Win10 and they are identical. And yet the behavior of BitDefender with respect to this "multicast discover" request is clearly different in Win7 and Win10.
I've tried disabling Firewall, and that does not eliminate the multicast blockage. But if I also disable "Advanced Threat Defense" well now that DOES eliminate the multicast blockage so that the LG app CAN connect with the DVR server.
However, interestingly, there is apparently something "residual" that remains from that first "successful connection to the DVR server from the LG client app" which when a second connection is attempted (e.g. powering off the TV, and then powering it on again, and relaunching the LG app), well now it is blocked by BitDefender and fails.
So with both Firewall and "Advance Threat Defense" disabled, the only way to have success connecting to the DVR server again is to reboot the PC (to restart with a brand new clean BitDefender). And now once again, that very first connection attempt after the reboot WILL WORK SUCCESSFULLY. But the second and subsequent connection attempts are again blocked.
The only way to see consistent 100% connection success from LG client to DVR server when operating in Win7 is to totally uninstall BitDefender. Now everything works perfectly and repeatedly. So it is obviously something about Firewall + Advanced Threat Defense operating in Win7 that is unhappy with "multicast discovery" but not unhappy with "broadcast discovery". And there is no problem whatsoever in Win10, where that "multicast discovery" now works problem-free all the time, thus allowing the LG app to always succeed in finding the DVR server.
So, that is the problem. I don't want to uninstall BitDefender in my Win7 world. But I would like to allow the use of the HDHR LG client app on the TV, and successfully connect with the DVR server running on the Win7 PC. Doesn't matter if I disable both Firewall and Advanced Threat Defense, because that will only allow a successful connection for the very first connection attempt following reboot. For second and subsequent connection attempts the multicast discover is blocked and fails (even though Firewall and Advanced Threat Defense are still disabled, clearly due to some residual data somewhere).
I don't believe any Firewall exception rule or Advanced Threat Defense exception program is going to solve this. Because if I totally disable both features entirely it still fails on second and subsequent attempts (obviously because of a bug), only succeeding on the first attempt.
==> It looks like an internal defect specifically regarding "multicast discovery", and only when running BitDefender on a Win7 machine. No problem on a Win10 machine.
Can I get some help from BitDefender Tech Support on this?
In support of this, HDHR "client" apps are available for smart devices, streaming devices, smart phones, etc. These client apps are available for (Android) NVidia Shield, (iOS) ATV4K, (Android) Samsung phones, (WebOS) LG OLED TV's, etc. So the "server" and any number of "clients" all exist on my home LAN, and work together as a whole-home DVR system allowing playing of live/recorded content via the Flex-4K tuners which is also network-based.
When the client apps launch they issue a "discover" command over the network, attempting to connect with the DVR server at whatever IP address it exists as. All but one of the client apps use a "broadcast discover" technique, which is absolutely not a problem for BitDefender. So all of these client apps have 100% success in connecting with the DVR server program running on the Win7/Win10 PC.
However one client app, namely the WebOS one that runs on the LG OLED TV, uses a "multicast discover" technique to reach the DVR server. I don't know why Silicon Dust programmed it that way but they did. And, unfortunately, there is some kind of blockage occurring in BitDefender for this type of request BUT ONLY IN WIN7! When the DVR server PC is booted to Win10, BitDefender running in that Win10 environment DOES NOT BLOCK THE "MULTICAST DISCOVER" and the LG app IS able to connect with the DVR server (again, running in Win10).
I've compared the BitDefender setups for both Win7 and Win10 and they are identical. And yet the behavior of BitDefender with respect to this "multicast discover" request is clearly different in Win7 and Win10.
I've tried disabling Firewall, and that does not eliminate the multicast blockage. But if I also disable "Advanced Threat Defense" well now that DOES eliminate the multicast blockage so that the LG app CAN connect with the DVR server.
However, interestingly, there is apparently something "residual" that remains from that first "successful connection to the DVR server from the LG client app" which when a second connection is attempted (e.g. powering off the TV, and then powering it on again, and relaunching the LG app), well now it is blocked by BitDefender and fails.
So with both Firewall and "Advance Threat Defense" disabled, the only way to have success connecting to the DVR server again is to reboot the PC (to restart with a brand new clean BitDefender). And now once again, that very first connection attempt after the reboot WILL WORK SUCCESSFULLY. But the second and subsequent connection attempts are again blocked.
The only way to see consistent 100% connection success from LG client to DVR server when operating in Win7 is to totally uninstall BitDefender. Now everything works perfectly and repeatedly. So it is obviously something about Firewall + Advanced Threat Defense operating in Win7 that is unhappy with "multicast discovery" but not unhappy with "broadcast discovery". And there is no problem whatsoever in Win10, where that "multicast discovery" now works problem-free all the time, thus allowing the LG app to always succeed in finding the DVR server.
So, that is the problem. I don't want to uninstall BitDefender in my Win7 world. But I would like to allow the use of the HDHR LG client app on the TV, and successfully connect with the DVR server running on the Win7 PC. Doesn't matter if I disable both Firewall and Advanced Threat Defense, because that will only allow a successful connection for the very first connection attempt following reboot. For second and subsequent connection attempts the multicast discover is blocked and fails (even though Firewall and Advanced Threat Defense are still disabled, clearly due to some residual data somewhere).
I don't believe any Firewall exception rule or Advanced Threat Defense exception program is going to solve this. Because if I totally disable both features entirely it still fails on second and subsequent attempts (obviously because of a bug), only succeeding on the first attempt.
==> It looks like an internal defect specifically regarding "multicast discovery", and only when running BitDefender on a Win7 machine. No problem on a Win10 machine.
Can I get some help from BitDefender Tech Support on this?
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Comments
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Hello @DSperber,
That is a very interesting behavior.
Sure, you may get in touch with our Technical Support Teams using one of the contact channels available at the following link: https://www.bitdefender.com/consumer/support/
Keep in mind that, as of January 14th 2020, Microsoft has ended standard support for Windows 7 and Windows Server 2008. Technical assistance and software updates from Windows Update are no longer available for the product.
It is strongly recommended for Windows 7 users to move to Windows 10 and Windows Server 2008 migrate to Microsoft Azure to avoid a situation where they would require service or support that is no longer available.
Bitdefender will continue to deliver support for Windows 7 and Windows Server 2008 R2 as long as there are no external constraints or dependencies on operating system updates and the technical effort can be covered in a timely manner.
Stay safe.
Premium Security & Bitdefender Endpoint Security Tools user
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