internet access blocked in bridged network

[kirsche40]

My Network configuration consists of following clients with listed static IPs:

1. Host (Win7): 192.168.0.100
2. Guest (Debian 6): 192.168.0.99
3. external embedded device (Linux): 192.168.0.1

I am using an USB2Ethernet Adapter at Host-USB which is configured in Bridged mode. Guest has 3 vNIC:

1. NAT (for Internet access)
2. Host-only Adapter (for SMB)
3. Bridged-Mode (to get a connection to external embedded device)

I was able to ping Host from Guest and from external embedded device. But I was unable to ping embedded device and Guest vice versa.

Changing adapter type and switching several services off did not change anything.

There are lots of advices in the internet which do not lead to any success. Eventually I stumbled over this post: ​http://forums.opensuse.org/english/get-technical-help-here/network-internet/422817-destination-host-unreachable.html#post2047168

The issue vanished after switching VM to use only one vCPU. In addition now I am unable to reproduce the issue by resetting the vCPU to 2.

I opened this bug report because this issue is well known (regarding the internet). I want to get this issue in scope of the developers and to provide a possible workaround.

[kirsche40]

I have to correct my initial report. I am able to reproduce the described behavior after each host reboot.