NAT Network is beating me!

[comemerda]

Hi forum!

I'm setting up a lab with VirtualBox and I'm currently stuck with something, that I assume, is related to NAT Network. My lab setup is very simple:

1 NAT Network created. Name: LabNetwork
3 Hosts:

2 x Client, with 1 NIC each, both belonging to "LabNetwork".
1 x Server, with 2 NIC, both belonging to "LabNetwork". One NIC is set for promiscuous mode to capture traffic.

The 3 computers have static IP addresses. Server has 10.0.0.2, and clients have 10.0.0.3-4.

Everytime I start my computers, the client under 10.0.0.3 can ping 10.0.0.4. Nothing else. 10.0.0.2 has an SSH server and Apache server. Both those ports are refused. If I go to the server, and ping 10.0.0.3, it fails for the first 3/4 packets, and then starts pinging.

After I do that, the client can access SSH and Apache with no problem. It's almost like the ping from the server to the client, "opens" the connections.

Has anyone seen anything like this? I'm really struggling trying to understand it. Any help/pointers would be appreciated.

Thank you!