Samsung Galaxy S6 Android 7.0 and OpenVPN Issues

[pbc]

Hi All,

I recently implemented OpenVPN on my Asus firmware router. Main thing was to ensure proper security when accessing my IP cameras remotely using an app like iVMS-4500.

All works fine with my Samsung S8 phone using the OpenVPN app.

However, I simply can't connect to anything on my LAN with my wife's S6 running Android 7.0 using the same OpenVPN app and settings.

OpenVPN establishes a connection just fine, but I can't access local IP addresses. Sometimes it connects after a prolonged wait to say my routers IP address or say my Brother printer's local IP address, but it never connects to my Network Video Recorder address which is where the cameras are. It definitely recognizes that the IP address is there (as when I setup my NVR in iVMS-4500 app the app recognizes I have 7 cameras installed on the NVR) but just hangs and eventually times out when I try to view a camera feed or try to directly connect to the local IP address of the NVR.

Also tends to hang and sometimes won't connect to other IP addresses.

Have ensured Power Saving mode is off and that the apps can use background data.

Any thoughts as to what is causing this or what setting I should try? It's driving me crazy at this point.

Thx!

 

[sfx2000]

Disconnect the WiFi, and try to access via 3G/4G/LTE...

 

[pbc]

Yes, I disconnect the wifi from the S6 before I connect via OpenVPN. The app shows a connection, but when I then go to a broswer and try to access a local IP address, it won't connect to anything (or occasionally does but takes forever).

 

[pbc]

... odd thing is My S8 is also using Android 7.0, but has no issues connecting to local IPs using OpenVPN.

 

[RMerlin]

Make sure you use TUN, as TAP requires root access.

Also check which OpenVPN app you are using - I believe there are some unofficial ones on the Google Play Store that might be different from Openvpn Connect.

 

[pbc]

Thanks....yes using the official OpenVPN connect app and TUN .

Baffled by this.

 

[pbc]

So tried a full factory reset on my wife's Galaxy S6. Checked again that all battery optimizing features were off, reinstalled OpenVPN, setup a new profile on my router and exported a new OpenVPN file to the phone.

Same issue. OpenVPN connects on the phone just fine. But trying to connect to IP addresses simply doesn't work. Worked for a couple addresses (like my Brother Printer and a Vera device) at first, but a few minutes later just hanged when I tried to reconnect.

Really don't get what could be causing this?

 

[pbc]

Still at it as it's driving me crazy. I've compared the log in files when connecting to OpenVPN from my S8 (which works fine) and then connecting with my S6. Save for the individual IP addresses of the phones themselves, the log files are identical.

Oddly, when I connect with the S8 file, I get these "warnings", which I do not get with the S6.

Sep 4 12:18:57 openvpn[1807]: xx.xxx.xx.210 WARNING: 'cipher' is used inconsistently, local='cipher AES-128-CBC', remote='cipher AES-192-CBC'
Sep 4 12:18:57 openvpn[1807]: xx.xxx.xx.210 WARNING: 'keysize' is used inconsistently, local='keysize 128', remote='keysize 192'

 

[pbc]

Also googled and saw this post from someone with a similar issue:

https://www.snbforums.com/threads/o...access-lan-network-or-services-rt-3200.36879/

So set my LAN DHCP DNS 1 server to 192.168.1.1 which is my router IP address, and then DNS2 to 8.8.8.8 as suggested.

Didn't do anything. Xentrk's post also suggests "We also had to set Accept DNS Configuration to Strict. I used to have exclusive", but I don't see that option anywhere in my XWRT-Vortex firmware router (a Netgear R7000 if that matters, firmware 380.68_1).

 

[pbc]

Well...figured it out, only took a couple days and a ton of trial and error...ha. In case anyone else has the same issue, in the OpenVPN app on Android I had to go into preferences, and then in VPN Protocol I had to specifically select "UPD" instead of the default "Adaptive".

Also, had to select "Force AES-CBC ciphersuites" as well which by default is not selected in the app.

Not sure why as my S8 works fine at default settings.

Don't need to make the change to the DCHP Server DNS1/2 as I noted above either.

Phew.

 

[pbc]

Just for fun I tried the same app settings in my Galaxy S8 and guess what? The same settings cause that phone to stop connecting to OpenVPN. Just plain weird.