Alright, .. i'm sorry - it sound like a troll answer.
But, .. actually the authentication is working. I get a connection and can ping a server for few (~ 10) seconds:
ping www.google.at
PING www.google.at (173.194.40.95): 56 data bytes
64 bytes from 173.194.40.95: icmp_seq=0 ttl=55 time=2.131 ms
64 bytes from 173.194.40.95: icmp_seq=1 ttl=55 time=1.891 ms
64 bytes from 173.194.40.95: icmp_seq=2 ttl=55 time=1.980 ms
64 bytes from 173.194.40.95: icmp_seq=3 ttl=55 time=4.043 ms
64 bytes from 173.194.40.95: icmp_seq=4 ttl=55 time=2.276 ms
64 bytes from 173.194.40.95: icmp_seq=5 ttl=55 time=3.025 ms
64 bytes from 173.194.40.95: icmp_seq=6 ttl=55 time=2.567 ms
64 bytes from 173.194.40.95: icmp_seq=7 ttl=55 time=2.207 ms
64 bytes from 173.194.40.95: icmp_seq=8 ttl=55 time=2.756 ms
64 bytes from 173.194.40.95: icmp_seq=9 ttl=55 time=2.329 ms
64 bytes from 173.194.40.95: icmp_seq=10 ttl=55 time=2.336 ms
64 bytes from 173.194.40.95: icmp_seq=11 ttl=55 time=8.740 ms
64 bytes from 173.194.40.95: icmp_seq=12 ttl=55 time=2.723 ms
64 bytes from 173.194.40.95: icmp_seq=13 ttl=55 time=9.126 ms
64 bytes from 173.194.40.95: icmp_seq=14 ttl=55 time=5.279 ms
64 bytes from 173.194.40.95: icmp_seq=15 ttl=55 time=2.633 ms
64 bytes from 173.194.40.95: icmp_seq=16 ttl=55 time=6.305 ms
64 bytes from 173.194.40.95: icmp_seq=17 ttl=55 time=2.983 ms
64 bytes from 173.194.40.95: icmp_seq=18 ttl=55 time=30.192 ms
64 bytes from 173.194.40.95: icmp_seq=19 ttl=55 time=89.586 ms
64 bytes from 173.194.40.95: icmp_seq=20 ttl=55 time=104.468 ms
64 bytes from 173.194.40.95: icmp_seq=21 ttl=55 time=6.056 ms
64 bytes from 173.194.40.95: icmp_seq=22 ttl=55 time=109.104 ms
64 bytes from 173.194.40.95: icmp_seq=23 ttl=55 time=93.288 ms
Request timeout for icmp_seq 24
Request timeout for icmp_seq 25
Request timeout for icmp_seq 26
Request timeout for icmp_seq 27
But as i said, after 8-10 seconds, the connection drops ..