Networking problem

[questioner_123]

Hi all,
I'm using Lubuntu on VirtualBox to simulate a small LAN of Linux computers, my host is Mac OS X. However, I am facing some network problems:

Mac OS X host: host A
Lubuntu guest: host B

What works:
- Ping from A to B and vice versa.
- Ping from B to hosts on the internet.
- Host A has complete internet access.

What doesn't work:
- rsh connection from A to B fails. Error: "select: protocol failure in circuit setup".
- rcp from A to B works (the file is transferred), but in the end I am getting an error: "select: protocol failure in circuit setup".
- Browser on B doesn't work.

My network settings are displayed on the attached images.