mwillis

NOTE FROM STAFF: THIS TOPIC IS NOW OBSOLETE. PREFER TUN/TAP DRIVER VERSION 9.21.2 INCLUDED IN EDDIE 2.11 AND HIGHER VERSIONS.
 
Hi there,
 
I'll be writing this hastily as I've spent about 6 hours diagnosing this issue. I'll revisit it later to add details if need be.
 
TL;DR: The latest TAP Windows Driver (9.21.0) is causing odd behavior when transferring data. Rolling the TAP driver back to (9.9.1) solved all my connection issues with the AirVPN client, my torrents and general web traffic.
 
THE ISSUE:
My torrent client would download/upload files correctly most of the time. Speed fluctuations are obviously normal, however I noticed a pattern where requesting ANY downstream data would essentially crash my torrents (bring them to 0 kb/s), then would skyrocket them back up to normal downloading speeds. I can reproduce this issue on the fly.
 
DESCRIPTION
1. Let's say I'm torrenting. Downloading at 1mb (or MB, I forget) per second.
2. Open Chrome, go to YouTube and watch any random video (or any webpage for that matter.)
3. Observe torrents nosedive to 0kb/s. At the same time, Chrome would constantly either crash or give a DNS error.
4. After about 5-15 seconds my torrents would start downloading/uploading correctly, while the YouTube video loads up correctly as well.
5. After the video buffers and requires more data to continue playing, the pattern repeats. This was obviously a very annoying issue and one that almost made me request a refund for my AirVPN subscription.
 
The torrents consistently nosedive to 0kb/s, and then rocket back to normal speeds when the competing data was requested/transferred.
 
I need to stress, that this is NOT limited to torrents or YouTube. It seems that any combination of (consistent transfers vs. a new transfer request) was enough to replicate this issue.
 
In other words, I was able to replicate the issue by browsing Facebook, while downloading a patch for a game on Steam. 
 
DIAGNOSIS:
1. Event viewer showed countless DNS errors (ERROR: The Peer Name Resolution Protocol service terminated with the following error: 
%%-2140993535) -> This was fixed by enabling the Peer Networking Group services inside services.msc. I may have disabled this months ago in hopes of streamlining my processes. This had no effect on fixing my main issue. However, it's nice to have less errors. 2. Incorrect usage of 1500 MTU. This one I suspected, but am still unsure if it caused any issues to begin with. I have since set a MTU of 1200 (until I have more time to test by xx10 values). 3. Basic malware testing / constant network resets and re-installing TAP and Wireless adapter drivers...this is where it gets interesting.  After hours of constant testing, I narrowed the main problem down to the TAP wireless adapter driver version that the AirVPN client is using. The current client is using (tap-windows-9.21.0 - May 2014) which technically is the most up-to-date driver. However, the previous driver (tap-windows-9.9.1) DOES NOT PRODUCE THIS ISSUE! SOLUTION:Roll-back the TAP driver to 9.9.1 (tap-windows-9.9.1.exe) using the executable from this page: http://swupdate.openvpn.org/community/releases/ 1. Within AirVPN settings, make sure that inside (preferences -> advanced -> general -> Microsoft Windows Only (on the right) that [Disable driver upgrade] is disabled. Otherwise, the AirVPN client will always update the TAP Windows driver to 9.21.0 upon launch. Be diligent in checking the forums for when a new TAP Windows driver is provided by OpenVPN, which will hopefully fix this issue! I'm sure that being on an older TAP Windows driver for an extended time may not be the most security-conscious decision, however I couldn't deal with the connection issues anymore. 2. Uninstall the current TAP driver (I used Device Manager ->Network Adapters -> TAP-Windows-Adapter-> Right-click and uninstall [and delete driver software].) 3. Download and install the older driver (9.9.1). From the link provided above. 4. Run the AirVPN client 5. Verify that any disconnects / drops / speed issues are resolved. If not, your issue may be less complicated than this and will require more troubleshooting. However, I will say that after scouring 10-20 threads on my issues, rolling back the TAP Windows driver helps. THOUGHTS / NOTES: The crazy thing is that I actually experienced THIS EXACT ISSUE while I was on PIA (another VPN) before moving to AirVPN. I chalked it to maybe a declining quality of service but they are probably using the 9.21.0 TAP Windows driver as well (the behavior I experienced was literally the same.) It seems that OpenVPN are aware of the quirks involving the 9.21.0 driver, so here's hoping that they're working on an update soon.  Of course, this advice is at your own risk. I just wanted to share my experience after literally 5-6 hair-pulling hours trying to debug this issue. As I write this post my traffic has been uninterrupted while watching some soccer videos on YouTube.  Please let me know if I can help any further! From other threads that I saw, this is a widespread issue. Many people are experiencing some sort of disconnect / dropouts / slow transfer speeds or in general weird behavior with unexplained causes. For me, the most recent 9.21.0 TAP driver was the cause. I still love you, AirVPN.