I am using VirtualBox 5.1.8 (and 5.1.18) on Windows 7 with guest Kubuntu 16.04
- Guest has only one network interface with mode = NAT
- Windows Firewall is Off (all profiles, all interfaces)
- I have Bromium and Pulse secure installed on host (Windows)
- I can ping any IP address on guest. ICMP packets go from VM to Host and onto the network and then back. I tested it using tcpdump on Linux (guest) and Wireshark on Windows (host).
- I cannot connect to any IP address beyond VM:
- Whenever I try to connect to any IP address outside VM I get "network unreachable" error
- tcpdump on guest system shows that default gateway responds with ICMP message "network unreachable" to TCP connection request message.
- Wireshark on host doesn't show any activity related to connection attempt.
- Connecting to the same hosts from host (Windows) box works perfectly fine.
- Bridging instead of NAT-ing works fine for the same guest system (when I set interface mode to Bridged connections work fine.).
- Installed FreeBSD as guest on the same host and got the same problem (can ping, cannot connect)
- One of my colleagues has exactly the same set up and it works fine for him.
My goal is to make NAT mode working again.
Tried so far:
- I tried upgrading VirtualBox to version 5.1.18 -- didn't help
- Downgrading VirtualBox to version 5.1.8 (last known working version)
- Rebooting after each re-install and re-configuration of VM
- Installing fresh VM and installing different OS (FreeBSD)
- Using "Nat Network" mode
So my questions are:
- What is causing NAT to drop TCP connections as inaccessible?
- How can I track down what is dropping TCP connections?
- How I can get NAT working again?
I cannot use bridged mode because I cannot have additional IP address on the network (besides the one I have for my Windows box). So I have to use NAT (or NAT Network)