How to provide Internet access to HOST from GUEST in virtualbox

Question

I am running Windows 7 guest OS on a Fedora Linux Host (in VirtualBox-6). I have a GSM USB modem. I can connect the modem to the Host machine and have Internet access to both host and guest, but can make neither USSD nor VOICE calls; Because the modem-provided linux driver (and software) source-code is too old to compile on my Fedora 30.

I can make USSD and VOICE calls from a Windows machine (i.e. from the guest), installing the modem-provided software; but it is preventing Internet access from the HOST!

gammu, wammu etc. did not work for me.

Now, I want to pass the USB modem to the guest OS, install it's Software there, handle voice+ussd calls, access Internet from that guest OS. But how to have Internet access from Host too? I think proxy server in the guest may be a solution but I cannot figure-out the way.

Answer 1

Put your guest's network interface in HOST_ONLY mode, and set up your host only network with the Virtualbox DHCP server disabled (File, Preferences, Network, Host-Only Network-> pick host only network from list->advanced settings->DHCP server). Detailed instructions here: https://www.virtualbox.org/manual/ch06.html

Use the internet connection sharing option on your windows 7 guest to share its internet connection to the host only network. You can google for instructions on how to set up the Windows 7 Internet Connection Sharing (ICS) function.

Your host will now think there is a gateway and internet connection inside the host_only network.