DNS leak

[REDACTED]

Hello,

I´m running Avast SecureLine on 4 devices, notebook and desktop PC with Windows 10 Pro and 2 iPhones. When I run DNS leak test, iOS devices pass it without issue but when I run the same test repeatably on both PCs, I´m leaking DNS (not in all tests but when I ran tests repeatably, in some).

I have tried steps mentioned here:

https://www.avast.com/en-us/faq.php?article=AVKB233#artTitle
https://www.avast.com/en-us/faq.php?article=AVKB248

So it shouldn´t be WebRTS issue and neither the second DNS related issue.

I can live with DNS leaks on my desktop at home but on my notebook which I use on different networks it´s a different story and if I won´t find a solution this VPN service loses it´s purpose (I do not care if I´m anonymous on internet itself, but I want to be anonymous on net between my computer and Avast VPN server).

PCs do not pass DNS leak test on neither newest Firefox (WebRTC tuned off through addon), Microsoft Explorer and Microsoft Edge.

Thanks for any further advices.



My original post about this issue in Czech language can be found here: https://forum.avast.com/index.php?topic=181430.0

[REDACTED]

Okay... 

It seems flushing DNS after each connection to VPN helps (ipconfig /flushdns) but didn´t have time for extensive testing yet. Will do so in next few days.

[schmidthouse]

Okay... 

It seems flushing DNS after each connection to VPN helps (ipconfig /flushdns) but didn´t have time for extensive testing yet. Will do so in next few days.

Let us know what you find.

[REDACTED]

It doesn´t work.

It looked like it did for a while... I was testing DNS leaks whole day and at late afternoon I got my first leak meaning it´s still not secure. I have checked Avast Secure line TAP adapter settings, there is even the static IP address for DNS server, so it should be ok but simply it´s not working (at least not reliably)...

Since yesterday I have tried 3 other VPN services. Currently I´m running NordVPN on trial and so far so good... Will let you know if this one works...

By the by... I have read on different forums (reddit maybe) that this - https://www.avast.com/en-us/faq.php?article=AVKB233#artTitle - is misleading, because it doesn´t work anymore under Win 10. Not sure, just mentioning what I read elsewhere.

[schmidthouse]

It doesn´t work.

It looked like it did for a while... I was testing DNS leaks whole day and at late afternoon I got my first leak meaning it´s still not secure. I have checked Avast Secure line TAP adapter settings, there is even the static IP address for DNS server, so it should be ok but simply it´s not working (at least not reliably)...

Since yesterday I have tried 3 other VPN services. Currently I´m running NordVPN on trial and so far so good... Will let you know if this one works...

By the by... I have read on different forums (reddit maybe) that this - https://www.avast.com/en-us/faq.php?article=AVKB233#artTitle - is misleading, because it doesn´t work anymore under Win 10. Not sure, just mentioning what I read elsewhere.

This DNS leaking has been posted about for some time now and seems is still a 'major concern'.
Hopefully Avast team will resolve this issue. DNS leaking should be, for obvious reasons, a priority!

[REDACTED]

I can confirm that NordVPN is working as intended.

Avast Premier is interfering with it though:

1) On notebook I have to turn Avast off before I connect to VPN, then I can turn Avast shields back on (probably some Firewall settings, who knows).

2) If Avast is on, in DNS leak tests I can see Avast DNS server in every test. If Avast is off, I can only see the VPN provider DNS as it ?should be?. I tried setting only firewall off but the Avast server, to my surprise, is still there - so to what part of Avast, if not to firewall shield, is this related (EDIT: It´s related to safe DNS component of Avast Premier)...

Interesting tinkering.

EDIT:

I have downgraded from Avast Premier to Avast Free Antivirus and all issues are gone (there is no firewall and no safe DNS option in free antivirus, yay). Looking back I had 80% tools from Avast Premier permanently turned off anyway, the only reason I liked that version were automated updates of outdated software - I can live without that.

[schmidthouse]

Just a thought. When installing Avast Premier did you use the Custom Install option in the installer?
When using Custom Install you can choose to NOT INSTALL the Firewall and all the tools/ added components in the 'Tools' column. Not then needing to disable anything.

[REDACTED]

That´s a good thought.

I have actually done a custom install of free antivirus and I have installed only 3 main shields + software updater + home network security.

I´m not sure what else I would install from Premier though. Well software updater from Premier would update automatically that´s true. And there is Antispam. Question is if those two added modules are worth the price of Avast Premier in a long term (I have active license for the product for at least a year yet).

[setchemist]

Okay... 

It seems flushing DNS after each connection to VPN helps (ipconfig /flushdns) but didn´t have time for extensive testing yet. Will do so in next few days.

I noticed a similar problem: DNS leak occurs when connected to SecureLine VPN.
I checked with https://dnsleaktest.com and it showed my original provider IP.
Recommendations on the same site worked well:
1) "ipconfig /flushdns" after the VPN connect,
2) "netsh interface IPv4 set dnsserver <connection name> static 0.0.0.0 both"
3) "netsh interface IPv4 set dnsserver <connection name> dhcp" after the VPN disconnect to enable web-surfing

However, I'm still disappointed by the fact that SecureLine allows DNS leaking.
I'm with Win7 and cannot find any settings like described in " https://www.avast.com/en-us/faq.php?article=AVKB233#artTitle" for Win8/10

[REDACTED]

I even got the "Secure DNS" option checked in Avast Internet Security... and I still got DNS leaks with SecureLine... Does this count for a refund?

[Davidek]

Hi All,

We have  release coming in the next couple weeks which will address this issue

Davidek

[setchemist]

Dear Davidek,

How is your release going?
SecureLine still has DNS leak.

Best wishes!

[Davidek]

Hi setchemist,

The release looks good and should be out soon.  I will post back in the coming days with specific info on that. Thanks,

Davidek

[setchemist]

I have updated Avast today,
but SecureLine still has the same DNS leak,
as before.
Is this problem going to be solved?

DNS flushing is really annoying,
and connection is lost in every 15-20 minutes,
so I have to repeat the procedure time to time.
It's definetely not the way the true VPN should work.

[schmidthouse]

This DNS issue should be a 'major priority' however it has been over a month since Davidek post on March 08.
Considering how long users have expressed their concerns, IMO this is simply not acceptable!