No TCP connection to network devices (except PCs and VMs)

[cpschnuffel]

Hi there,
I've searched the whole forum but found nothing that matches my problem (sorry: my challenge ):

I have a Windows 7 guest (network bridge, VirtualBox 5.0.10) running on a Windows 7 host. Guest and host have two different static IP addresses within the same IP range (192.168.16.X), and I am able to connect via TCP/IP from guest (as TCP client) to host (as TCP server) and vice versa on any available port. I'm also able to connect via TCP/IP from this guest to another guest2 (running on another host2) with different static IPs (but within the same IP range) in both directions.

I am also able to access to network drives (running on a NAS) from the guest or pinging all network devices (including those described below).

But: I am *NOT* able to connect from this guest (as TCP client) e.g. to the internal website of my Fritz!Box or to the internal website resp. a specific control port (5025) of a measurement device (connected via LAN), both with different static IPs and of course within 192.168.16.X. From host (or host2) there's no problem to connect to them.

Summary:
guest <-> host: OK
guest <-> guest2: OK
guest <-> host2: OK
host -> <network device>: OK
guest -> <network device>: FAILED

For me it doesn't seem to be a firewall issue (because of the connections guest <-> host and guest <-> guest2); any suggestions?

Best regards from Berlin
cpschnuffel

[cpschnuffel]

I must correct myself: I only have TCP connection from guest to its host and vice versa:

guest <-> host: OK
guest <-> guest2: FAILED
guest <-> host2: FAILED
host -> <network device>: OK
guest -> <network device>: FAILED

In the meantime I uninstalled my current version of VirtualBox (and deleted the program files folder as well) and then installed VirtualBox 5.1.22 (including guest additions): No change.

Any idea is highly appreciated.

Best regards, cpschnuffel

[cpschnuffel]

Problem solved !

After all it was a firewall issue: My firewall on the host (not the internal one from Windows 7) didn't have a rule for the TCP/UDP packets from/to the guest (because from the firewall's point of view they are not application-related), so it blocked this communication silently. I added a rule for incoming/outgoing TCP and UDP packets, and now it works.

Regards,
Carsten