Unable to connect to VPN (L2TP / IPSec PSK)

[GrilledPizza]

I'm unable to establish a connection to my VPN, type L2TP/IPSec PSK using an IPSec pre-shared key (local and external). The VPN is running on a Synology NAS (model DS713+ with DSM 5.1-5022 Update 2).

After configuring it hangs on "Connecting..." and after a while it says "Disconnected". When I look at my VPN server logs, nothing seems to be happening on the server as if nothing tried to connect.

My old LG Optimus 2X running android 2.3.4 is able to connect using exactly the same settings and within the same environment, which makes me quite sure about the Xperia Z1 Compact being the culprit.

Software

14.4.A.0.157

Android

4.4.4

Model

D5503 (unbranded)

Is there a way to debug this on the Z1 Compact? Or is this an known issue? If so, is it going to get fixed?

//EDIT:

Apparently I'm not the only one with this issue on Xperia devices:

1. http://talk.sonymobile.com/t5/Xperia-Z-ZL-ZR/VPN-Xperia-Z-don-t-connect-S3-mini-does/m-p/935450/high...
2. /t5/Xperia-Z3-Compact/cannot-make-a-l2tp-vpn-connection/td-p/936805
3. /t5/Xperia-Z2/VPN-L2TP-not-working-Android-4-4-3/td-p/843177
4. http://forum.xda-developers.com/xperia-z/help/l2tp-vpn-connection-fails-t2865147
   

[md_sonyman]

I have the same problem with connecting to Draytek devices. Windows/Mac/Iphone can but my Xperia Z3 cannot. L2TP/IPSEC PSK 96bit don't slove the problem.

[Rickard]

Sorry to hear that.

It seems Draytek provides their own app for this. What if you download this app and try to connect using it: https://play.google.com/store/apps/details?id=com.draytek.smartvpn

[MartinK1]

Just wanted to add, that vpn from Android to Microsoft servers has been a problem for ages... One solution has been to use reversible encrypted passwords on the server...

Its sad that chap / mschap isnt supported and even sadder that sstp isn't supported out of the box

[StefanZ5]

I am using a z5 compact with build 32.0.A.6.152 and facing the same issues. Neither l2tp nor ipsec connections work.

Is there a fix or workaround?

[eskiddy]

Hi Rickard,

today my Sony Z1C got 14.6.A.1.216.

The problem still exists. I tried to connect with the vpn settings "l2tp psk" and "l2tp psk 96 bits".

Any other suggestions?

Thank you.

[Cbratt]

Same problem here, Z5c with 32.0.A.6.200 

[OkiSeb]

Same problem for me Xperia Z5 32.0.A.6.200  

I am very disappointed that a brand like Sony don't be able to fixe a problem for so many years !

The VPN is a priority for me so I'll return this phone !

[AsIWasGoing]

I have also just purchased a Z5 Compact, only to discover that the Android VPN client does not work!  It has been no problem on my SIII and Nexus 7, so how come it's a problem for Sony (and a long standing one it seems)?

I can't believe that a stock Android app is so broken.

My build number is 32.0.A.6.200.

[Rickard]

I'm sorry to hear that.

Work is ongoing to include a fix for VPN compatibility in upcoming software updates for Z3+ and Z5 devices.

The fix is currently rolling out for Z1, Z2 and Z3 devices.

[Haldi4803]

:smileyangry::smileyangry::smileyangry:

I've been testing around for over 40 minutes with L2TP Ipsec and even asked a friend to test on his Galaxy S6 to figure out why PPTP works easily and this does not.

At least it's the first item in google search ^^

Does anyone know why Synology uses a 96bit PSK? What is the normal PSK length ?