How can I make 3 VMs connect with each other as well as internet without using bridged adapter in Virtualbox?
I don't want to use bridged adapter because I use WiFi and this combination often doesn't work. I need to connect with internet to be able to download packages, and connect with each other so that I can form a Kubernetes Cluster.
I want to connect to them via SSH from another remote machine (using same or different network).
You may be able to create a new bridge for the three VMs, and also have them all inside a NAT network from your Host. (You may also find that putting them on the same NAT network allows them to contact each other - I haven't tested VirtualBox recently to check this.)
To allow incoming ssh connections to each machine you're going to need to Port Forward from your Host. Each VM will need a different port, for example, 50001, 50002, 50003.
An option is to use the host-only adapter, and route via IPtables. This is from host-only network into Wifi, you may need to set up the other direction too (duplicate first line and switch input and output interface and put the host-only net´s IP range as destination instead of source).
sudo iptables -I FORWARD -o wlp58s0 -i vobxnet0 -s 192.168.58.0/24 -m conntrack --ctstate NEW -j ACCEPT sudo iptables -I FORWARD -m conntrack --ctstate ESTABLISHED,RELATED -j ACCEPT sudo sh -c "echo 1 > /proc/sys/net/ipv4/ip_forward" sudo iptables -t nat -F POSTROUTING sudo iptables -t nat -A POSTROUTING -o wlp58s0 -j MASQUERADE The host-only network (name, IP) can be configured via Tools -> Network Manager.
Why not simply create a NAT network? I wanted to open up the virtual network only occasionally via script.
