ASUS RT-86U OpenVPN "Drop_Caches: 1"

[gupfuppington]

Hi all,

I've had no issues with my OpenVPN settings with various devices but now have one with my new NVIDIA Shield Pro where the connection just drops.
I've attached a screenshot of the traffic analyzer page which shows it dropping then shooting back up.
I'm sure the issue is on the NVIDIA end but there's not much I change in the device settings and was wondering whether there's something I can do on the Merlin side.

No matter what I'm streaming, the connection just drops every 10 minutes or so, below is how it looks in the log;

Mar 20 21:41:58 ovpn-client1[19802]: VERIFY OK: depth=2, C=VG, O=Surfshark, CN=Surfshark Root CA
Mar 20 21:41:58 ovpn-client1[19802]: VERIFY OK: depth=1, C=VG, O=Surfshark, CN=Surfshark Intermediate CA
Mar 20 21:41:58 ovpn-client1[19802]: VERIFY KU OK
Mar 20 21:41:58 ovpn-client1[19802]: Validating certificate extended key usage
Mar 20 21:41:58 ovpn-client1[19802]: ++ Certificate has EKU (str) TLS Web Server Authentication, expects TLS Web Server Authentication
Mar 20 21:41:58 ovpn-client1[19802]: VERIFY EKU OK
Mar 20 21:41:58 ovpn-client1[19802]: VERIFY OK: depth=0, CN=de-fra-v099.prod.surfshark.com
Mar 20 21:41:58 ovpn-client1[19802]: WARNING: 'link-mtu' is used inconsistently, local='link-mtu 1633', remote='link-mtu 1581'
Mar 20 21:41:58 ovpn-client1[19802]: WARNING: 'auth' is used inconsistently, local='auth SHA512', remote='auth [null-digest]'
Mar 20 21:41:58 ovpn-client1[19802]: Outgoing Data Channel: Cipher 'AES-256-GCM' initialized with 256 bit key
Mar 20 21:41:58 ovpn-client1[19802]: Incoming Data Channel: Cipher 'AES-256-GCM' initialized with 256 bit key
Mar 20 21:41:58 ovpn-client1[19802]: Control Channel: TLSv1.2, cipher TLSv1.2 ECDHE-RSA-AES256-GCM-SHA384, peer certificate: 2048 bit RSA, signature: RSA-SHA256
Mar 20 21:52:36 kernel: httpd (19453): drop_caches: 1

There's link-mtu and auth warnings that I've had no issues with for months but the drop_caches: 1 line is new and is what inevitably causes the signal drop.

Extra info;

Router - ASUS RT-AC86U (Merlin 386.5)
Device - NVIDIA Shield
VPN - Surfshark
Everything works fine when I've disabled the device from the VPN director page
I'd like to avoid using an ethernet cable for now
I've attached a screenshot of my VPN settings

Thanks for any help. Apologies if I missed out any info, still fairly new to this.
Neil

 

[ColinTaylor]

The drop_caches message appears when you log into the router's GUI.

We'd need to see the part of the log that shows the VPN disconnecting to understand more.

Your VPN screenshot is too small to read.

 

[gupfuppington]

Hi Colin,

Ah sorry, thought the drop_caches was the major issue.

I've just attached an update of the log as a .txt file and below is my experience;

19:54 - buffer
19:55 - buffer

Nothing is logged at them times but is there something happening before?

Sorry, my screenshot got compressed, hopefully this is clearer - https://ibb.co/4VVmP3R

Thanks,
Neil

 

[ColinTaylor]

19:54 - buffer
19:55 - buffer

OK, I see you restarting the VPN client at 19:47:30 and it's fully connected by 19:47:35. Then there's nothing at all.

So I think I misunderstood what you were describing. When you said "the connection just drops" I thought you were saying the router's VPN client was disconnecting. But there's nothing in the log to suggest that's happening. So what connection are you talking about. Is it simply that the Shield Pro is pausing/buffering playback rather than any network connections "dropping"?

 

[kofii12345]

Could it be connected with broken SMB/NFS Shield Pro connection over wifi? (https://forum.kodi.tv/showthread.php?tid=348860, https://www.nvidia.com/en-us/geforce/forums/shield-tv/9/464364/kodi-smb-freezes-over-wifi/)
It works with cable connection and probably the problem is connected with asus routers.
Could you test cable connection?

 

[gupfuppington]

Sorry late reply to this, I couldn't test a wired cable (a bit too far), and yes Colin I meant buffering rather than dropping.

Not really an issue anymore though as I had a look at pages like this and have just upgraded to a AX86S. Same settings and nothing is buffering!

Thanks for the responses!