BD 2020 blocks Windows 10 mobile hotspot in two different ways!!

Back in 2019 I posed a question here about BD 2019 seemingly blocking my use of Windows 10 "mobile hotspot" functionality from my laptop. Specifically the issue was "could not get an IP". Of course a complete uninstall of BitDefender brought back full hotspot functionality. Clearly the problem was with BitDefender.

After much research and experimentation (and no help from BitDefender tech support, I might add), I determined for myself that this first issue stemmed from BitDefender Firewall. It was blocking access to the IP address, i.e. the DHCP server associated with WIndows 10 mobile hotspot. Once I figured this out and created a Firewall exception rule for local address (all apps, all protocols, both directions) sure enough I was now able to get an IP address successfully to my phone, Roku, other wireless devices, etc.

However all of these connections still were not 100% successful. Although they did get an IP address assigned, they were still blocked in some other way by BD 2019. They either showed "green check" for connection status, but "red X" for internet status. Or, the phone showed "connected without internet" on the WiFi connection status, again an indication of IP assigned but blocked from actually getting to the internet.

Only solution that I knew of in order to use Win10 mobile hotspot from the laptop: uninstall the product completely. Then hotspot worked perfectly.

It would have been helpful if I'd ever gotten constructive advice or instructions from BitDefender support to advise me as to probably what else needed to be added as "exceptions" or "rules" and then in what protection categories, but I never got any such support or help.

Well now I'm using BD 2020, and of course the same issue persists. Whatever is going on, it's either still unfixed if a bug, or I'm still missing the required exceptions to be added.

But at least I started off by adding the now known required Firewall exception for So my new research (again on my own, not with the help of BitDefender support) was to try and explore what else I might need to tweak in order to maybe hopefully finally get not only a successful IP connection but now also full access to the internet. And the obvious protection category to be delved into must be "online threat prevention".

I have finally determined that if I uncheck (i.e. disable) THREE of the sub-features of "online threat prevention" then I can now connect to the hotspot from my phone: (1) web attack prevention, (2) encrypted web scan, and (3) network threat prevention. With all three of these items OFF I CAN CONNECT WITH INTERNET! And if I turn on any one, two or all three, I am once again blocked from having a successful connection with internet.

So at least it's now known what particular items within BD are involved. As to how to code an exception for Windows 10 mobile hotspot, well I don't know . That is for BitDefender Tech Support to tell me. Or, if this is a newly expressed problem description that nobody else has ever asked about before now (sure seems hard to believe), why hasn't it been either FIXED or the required workarounds been published in the FAQ somewhere?

For now, I have TOTALLY UNINSTALLED BITDEFENDER 2020 ON MY LAPTOP, because I need to use Win10 mobile hotspot. Of course I'd like to have it reinstalled, but will not until BitDefender Tech Support advises me as to what additional exceptions I must add. and to where.

But at least I have done the pre-diagnosis to confirm that both (a) Firewall exception for, as well as (b) some still unknown exceptions for "online threat prevention", in order to allow full normal operational use of Windows 10 mobile hotspot. If BitDefender Tech Support was unaware of this problem until now, you are now at least aware of it. And you know now exactly what the problem is, and where within BD are the "workarounds" if turned off totally.

I don't want to turn off (1) web attack prevention, or (2) encrypted web scrn, or (3) network threat prevention, as I've had to in order to inhibit BD 2020 from breaking Win10 mobile hotspot completely.

I only want to know from BitDefender Tech Supportwhat exceptions I need to add in order to allow Windows 10 mobile hotspot to actually work properly with BD installed.

Best Answer

  • DSperber
    DSperber ✭✭✭
    Answer ✓

    I finally got some tech support from BitDefender.

    They advised me to create one more Firewall rule, this time allowing all apps, all networks, any protocol, both directions, and Advanced -> Custom Remote Address ENABLED: ports 67,68. I don't even know what that means and I never would have dreamed it up on my own. But they told me to add it, and I did. And apparently it was the secret sauce!

    • DHCP server dynamically assigns IP address on demand to the DHCP clients.
    • DHCP uses UDP port number 67 as destination server and port number 68 for the client.

    So this second Firewall rule now supplements my original first Firewall rule which was for all apps, all networks, any protocol, both directions, and Advanced -> Custom Local Address ENABLED: IP and which provided access to the DHCP gateway server of Windows 10 Mobile Hotspot.

    I also then went back into "online threat prevention" and re-enabled the three sub-features I had previously disabled (to at least temporarily get one or two connects to work successfully until I could get a real proper 100% solution). So (a) web attack prevention, (b) encrypted web scan, and (c) network threat prevenetion are now ALL ONCE AGAIN RE-ENABLED AND ACTIVE!

    And, remarkably, everything is now working perfectly!!! I can disconnect and reconnect as many times as I want to, all on the same single ongoing hotspot session, without so much as a hiccup. And connection is rapid, stable, and repeatble, no matter how many times I disocnnect and reconnect.

    I do believe this one is finally resolved!! Thank you to BitDefender support for finally helping out here.

    Two firewall rules, and you're home free. Windows 10 Mobile Hotspot now works perfectly with BitDefender installed and fully operational with no sub-features disabled.


  • DSperber
    More information derived from experimentation, about the INCOMPATIBILITY of BitDefender 2020 with Windows 10 mobile hotspot functionality.

    Turns out that even with the three sub-features of "online threat prevention" TURNED OFF (web attack prevention, encrypted web scan, and network threat prevention), my phone's successful connection to the laptop's hotspot only occurs once, or maybe twice, or in rare cases three times, before NEVER AGAIN CONNECTING unless I first disable hotspot on the laptop and then re-enable it. Now, once again, the phone can connect.

    This is 100% repeatable. Don't have hotspot enabled on the laptop, then enable it. Now the phone can connect via its WiFi connection feature. Then turn off WiFi on the phone, to drop the connection with the laptop's hotspot (and wait until the status on the laptop shows that the phone connection has disappeared). Then turn WiFi on the phone back on, and 90 times out of 100 it will not be able to reconnect this second time and 10 times out a 100 it will be able to. If it is successful, once again turn WiFi off on the phone and wait until the laptop confirms dropping the connection, and then once again turn WiFi on the phone back on. Almost never will it reconnect this second time... with the hotspot on the laptop still in that same original "session". And if it does actually reconnect this second time, just repeat that sequence one more time, and now only once out of 20 tries have I seen the phone reconnect a third time successfully while that same original hotspot "session" on the laptop is still running.

    In contrast, if the phone WiFi is turned off and then the laptop hotspot session is stopped, and then the laptop session is started anew, and then the phone WiFi is turned on, well now the phone connects successfully... on this very first connection of the new hotspot session. But again, turn off phone Wifi, wait, and then turn phone WiFi back on, and 97 times out of 100 it will not reconnect successfully for a second time during the current second laptop hotspot session.

    Etc., etc.

    And of course, in complete contrast to how things behave with BitDefender installed on the laptop with those three online threat prevention sub-features disabled, all I have to do is completely uninstall BitDefender and the phone has no problem connecting when WiFi is turned on to the very first laptop hotspot session. Then turn off WiFi on the phone, wait, and turn phone WiFi back on, and reconnection to the laptop hotspot is 100% successful. Repeat the sequence, turning off phone WiFi and wait, turn phone WiFi back on, and reconnection to the laptop hotspot is again 100% successful. And all still on the same single first laptop hotspot session. No need to turn off and turn back on the laptop hotspot. You can just leave it on forever and toggle the WiFi on the phone over and over repeatedly, and it will ALWAYS RECONNECT!!!

    In summary, BitDefender as delivered and installed by default with whatever features are always active, appears absolutely 100% incompatible with Windows 10 mobile hotspot even with the needed firewall rule for in place. Getting past the BitDefender Firewall is only part of the job. The rest of the job appears impossible to overcome with 100% success and repeatability. This is really terrible, and apparently the BitDefender engineers don't care because this has been the case for several years now that I've reported it.

    If there is some other exception or rule which must be coded somehow somewhere in order to allow my phone to coexist happily and problem-free with BitDefender 2020, I'd like BitDefender Tech Support to tell me what it is. I have described in excruciatingly clear detail exactly all you need to do in order to prove for yourself that THIS IS A TOTAL FAILURE!!

    It would be very helpful to me as a paid customer of 50-machine license to know from Tech Support exactly what I must do in order to get this to work. You are now fully aware that your product is 100% incompatible with proper operation of Windows 10 mobile hotspot.

    NOW PLEASE TEST IT FOR YOURSELF, and then fix whatever's broken, or figure out what exceptions or rules must be user-coded in order to overcome the 100% failure of the product and could justify my continuing to pay for the product instead of just uninstalling it as my "solution".

    Tech Support: please respond to this question.
  • Mike_BD

    Hi @DSperber!

    Glad to hear my colleagues provided a solution, but thrilled to have you share this here, so that others may benefit from your experience. True community attitude.



    Intel Core i7-7700 @ 3.60Ghz, 64GB DDR4 || Gigabyte nVIDIA GeForce® GTX 1070 G1 8GB || WD Blue NAND 500GB + 1TB

  • It was happening to me because svchost was being blocked. So I made this rule by setting the hotspot adapter as Home/Office and it works.

    Restart PC to take effect

  • DSperber

    I believe the Firewall rule you've coded was first mentioned in another thread here regarding BD blocking gaming on a local area network using XBox. There was some commenting on that thread that this "opening up everything to SVCHOST" is a very dangerous and inappropriate "solution", although it worked.

    So, just as in my thread here which centers on Win10 Mobile Hotspot being blocked, I'm sure that SOME Firewal rule is needed to resolve the issue, but not one which un-protects SVCHOST. In my case here, I eventually got some tech support from BitDefender and they provided me with the actual additional Firewall rule I needed:

    (2) All apps, all networks, any protocol, both directions, and Advanced -> Custom Remote Address ENABLED: ports 67,68.

    This second rule opens the two ports used by Mobile Hotspot client and server, and is required in addition to the first rule I'd already created which is:

    (1) All apps, all networks, any protocol, both directions, and Advanced -> Custom Local Address ENABLED: IP

    This first rule allowed access to the DHCP gateway server which is part of Windows 10 Mobile Hotspot functionality.

    These TWO rules together is what is currently required. There is no further need for anything further, and in particular there is certainly no need to un-protect SVCHOST which seems truly inappropriate as was already pointed out in the other XBox gaming thread.

    And one more point. I had a "chat" session with BitDefender tech support on this subject of Win10 Mobile Hotspot. Sometime after the session completed I received an email follow-up that provided me with the following new information:

    "I have looked into the case and it seems that the situation is caused by an issue that has already been acknowledged by our development team. We are currently working on a fix which will be done by means of automatic update and won't require any additional action on your end.

    I will get back to you with an update regarding the fix as soon as we have one."

    In other words, although I'll believe it when I see it, it sounds like BD development is going to make some built-in modifications to the product which will provide built-in automatic support for allowing Win10 Mobile Hotspot WITHOUT REQUIRING ME TO CODE ANY ADDITIONAL FIREWALL RULES OF MY OWN. I assume they will simply implement in the product itself the functional equivalent of the two manually coded rules above which I currently have in place and which 100% solve the problem.

    If/when I actually receive word from BD support in the future that this specific product update has finally been completed and "pushed out" as normal version maintenance I will test it out by removing my two Firewall rules. And I will report back here (and to BD support) whether or not I agree that they have truly and finally corrected BD to finally be 100% compatible with Win10 Mobile Hotspot.