I'm using kubernetes proxy to talk to my kube dashboard

I'm running kubernetes on vagrant

In the browser I usually see the dashboard, but after some time passes I end up with the following instead in the browser:

Error: 'dial tcp 10.2.99.7:9090: getsockopt: no route to host'
Trying to reach: 'http://10.2.99.7:9090/'

At the same time in the terminal I see:

$ kubectl cluster-info
Kubernetes master is running at https://172.17.4.101:443
Heapster is running at https://172.17.4.101:443/api/v1/proxy/namespaces/kube-system/services/heapster
KubeDNS is running at https://172.17.4.101:443/api/v1/proxy/namespaces/kube-system/services/kube-dns
kubernetes-dashboard is running at https://172.17.4.101:443/api/v1/proxy/namespaces/kube-system/services/kubernetes-dashboard

The only way I can find to fix this so far is to do a vagrant halt && vagrant up but this is quite disruptive.

I've tried killing and restarting kubectl proxy - does not change the situation.

All of this is running on a MacOSX laptop btw.

Thanks very much.