UTM 9 - Hyper-V - slow Network Speed

Hello,

I am using Hyper-V Server 2008 R2 and have currently some problems with the network speed.

The Setup is:

Internet NIC -> Astaro -> private NIC -> Client

I have currently 7 MB/s with this Setup.

If i change the Setup to:

Internet NIC -> Client

I have up to 20 MB/s.

I tryed both normal and legacy adapter.

IPS is disabled.

RAM ~60%
CPU 5%
SWAP 0%

Any Tipps ?

Thx

Greetings