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l2tp problem

Posted: Sat Jun 10, 2017 3:28 pm
by q1w2e3
hi, i'm use softether on ubuntu 16.04.02, odroid xu3(similar rpi)

openvpn work fine, but l2tp is the problem on both desktop and android phone.

On windows desktop, i can't connect vpn server using l2tp
720 error(A connection to the remote computer could not be established. You might need to change the network settings for this connection) has occured. As you can see the log file, A PPP protocol error occurred, or the PPP session has been disconnected.

On android smart phone, connection is successful, lock icon is shown. but internet isn't work(browser alarm that 'can't find dns address'.) on the log file, program just try to create udp session.

what should i do?

Re: l2tp problem

Posted: Sat Jun 10, 2017 5:31 pm
by vimal7370
Try setting DNS server 1 to 8.8.8.8
and leave DNS server 2 blank and see if that works (168.126.63.1 is a valid DNS server as well, but I am not sure if any DNS service is running in the VPN server).

Also try installing a console application on your mobile and see if you can ping to any remote ip, and also check the default route.

Re: l2tp problem

Posted: Sun Jun 11, 2017 6:51 am
by q1w2e3
i follow your order. but problem is still remain.
On smart phone console, it can ping any ip address but can not ping any dns name(url). example) can ping 8.8.8.8, but can't ping www.google.com
i guess vpnserver couldn't received the data from dns server.

Re: l2tp problem

Posted: Thu Jun 22, 2017 6:45 am
by thisjun
Did you configure that the Android uses the VPN as default gateway?
http://www.softether.org/4-docs/2-howto ... ient_Setup

Re: l2tp problem

Posted: Fri Jun 23, 2017 10:00 am
by q1w2e3
Are you talking about 'Forwarding routes' field?
I entered 0.0.0.0/0, but nothing is changed.

Re: l2tp problem

Posted: Thu Jul 06, 2017 7:53 am
by thisjun
Could you show the logs after changing settings?

Re: l2tp problem

Posted: Thu Jul 06, 2017 10:39 am
by q1w2e3
168.126.63.1 is dns server.
192.168.0.1 is home router.
192.168.0.152 is odroid.
192.168.2.1 is virtual network interface.

Re: l2tp problem

Posted: Thu Jul 20, 2017 6:28 am
by thisjun
If DNS (168.126.63.1) doesn't work, please try to delete 168.126.63.1 from SecureNAT.

Re: l2tp problem

Posted: Sat Jul 22, 2017 12:45 pm
by BalRoG
q1w2e3, i have the exact same problem, fighting with it for 3 days.
Android phone connects without any problem, and can connect to local http.
But Windows Server 2016 doesn't, i tried to tune all the possible settings, including that represented here, but with no luck. still error 720.
Please help!

Re: l2tp problem

Posted: Thu Aug 03, 2017 5:59 am
by thisjun
>BalRoG

Did you choose L2TP/IPSec PSK as protocol?