VirtualBox host-only network, cannot ping host from guest

Solution 1:

Your host PC has multiple networking interfaces and multiple IP addresses. Its difficult to say for sure, but based on the information you've provided it looks like the IP 192.168.0.103 is likely your standard network interface. VirtualBox has created a second network interface called the "VirtualBox Host-Only Ethernet Adapter" and given that adapter the IP of 192.168.33.1.

Since you can ping 192.168.33.1 from your guest VM you CAN ping the host computer from the guest, but you can only ping the interface/IP that is shared with the VM. Your PC will not route the network traffic from the host-only interface to your real network interface.

As for capturing traffic using Wireshark, it appears the Wireshark can only use physical interfaces and the host-only interface is a software interface created by VirtualBox so you likely won't be able to capture from it.

Solution 2:

I had the same setup - a Windows host with an Ubuntu VM on it. And the same problem. I could ping the guest from the host, but not the other way around. I was using a bridged adapter in the VM settings, and I entirely removed the Host Only adapter VirtualBox created...

The problem turned out to be the Windows Defender Firewall! As a shotgun approach, I just disabled it entirely, and tested... presto!

Ideally, one would want to add a firewall rule to open a pinhole for a specific ip range, port, protocol... Try the shotgun first to see if you have the same essential issue.