Host only networking problem - Win7 host and Ubuntu Guests

[Tariq]

I am running vbox 4.2.12 and I'm having a problem with host-only networking that I'm hoping to get some suggestions on. I have a windows 7 enterprise host (i7, 8 cores, 16Gb RAM), running two Ubuntu 12.04LTS guests (one desktop, one server). Each guest has been allocated one cpu core, 1Gb of RAM and an 8Gb fixed disk image. I'd like to use host only networking and the vbox network configuration does have the host only interface installed, with DHCP enabled.

Host-only interface: 10.0.0.1/24
DHCP server address: 10.0.0.100
DHCP pool: 10.0.0.101 - 10.0.0.200

Each guest receives an IP from the virtual DHCP service successfully and each guest can ping the other guest. For some reason however, I cannot ping or otherwise connect to the host only interface from the guest instances. I can however ping the guest instances from the host.

NAT works fine, but I want to use host-only to keep the VM's reasonably isolated from office network that I'm attached to. I planned on using a local proxy app on the host to selectively grant access to web services when needed.

I've run tcpdump on each Ubuntu instance as well as Wireshark on the host to track the packets as they traverse the system. The ping packets from the guests to the host interface ellicit no response, but a DHCP or ARP request gets answered just fine. I've also run the proxy instance on the host and telnet's to the proxy port (tcp/8080) also go unanswered.

The first thing I've thought of is the local machine firewall (running native Windows firewall), but I think I've poked a hole through to allow access from/to the 10.0.0.0/24 subnet, so I don't think that's the cause (unless I'm off my rocker and misconfigured it somehow - its possible)

Any help or suggestions would be appreciated.

Thanks,

Tariq

[noteirak]

Can you ping a guest FROM the host?

[Tariq]

Yes, from my windows host I can ping both of the Linux guests.

Tariq

[noteirak]

If you can ping from the host to the guests, but not from the guests to the host, it's a firewalling issue on the host.