Per default a Vagrant box uses the NAT interface as default gateway. This results into an incorrect primary interface configuration when running 'oaconfig install'. The primary interface will be the NAT interface and NOT the interface used to access the WebUI.
The problem comes into account when you try to add a remote node in a multinode setup. Based on the interface information stored in the database the remote node tries to communicate with the master node via the IP address of the NAT interface which will finally fail. This means it is not possible to communicate from remote -> master node, e.g. when browsing the API on the remote node.
To prevent this, the default route must be reconfigured to allow oaconfig install to choose the correct primary interface.