The problem was that after Cisco VPN was connected, guest could not be resolving the DNS as VPN changes the dns servers. Guest was still hitting the old dns configured and VPN was not allowing them.
The solution of setting VirtualBox to use host resolver neither VBoxManage modifyvm "kubespray_k8s-1_1549866615143_75146" --natdnshostresolver1 on
nor VBoxManage modifyvm xxx --dnsproxy1 no worked. Also, do not set both, VirtualBox drops one of them and you can check them
in VM logs.
The solution is to install dnsmasq on host brew install dnsmasq and then set the VBoxManage modifyvm xxx --dnsproxy1 on.
Then the guest vms could connect to internet.