vif-route-qubes fails when setting up a 'provides network' VM

[tetra...@danwin1210.me]

I am trying to duplicate a previously-successful configuration of a
Debian based ProxyVM/'provides network' VM.

However with the new VM (call it proxy2) the client VMs are
unable to reach the proxy (ping returns 'Destination Host Unreachable').

The proxy2 VM only shows two network interfaces in the output of
`ifconfig`: eth0 and lo

The (working, older) proxy1 VM shows three network interfaces in the
output of `ifconfig: eth0, lo, and vif22.0

When I start a client VM, the following lines appear in the output of `journalctl` on proxy2:
Sep 30 16:08:03 proxy2 root[5360]: /etc/xen/scripts/vif-route-qubes: offline type_if=vif XENBUS_PATH=backend/vif/51/0
Sep 30 16:08:03 proxy2 root[5372]: /etc/xen/scripts/vif-route-qubes: Writing backend/vif/51/0/hotplug-error /etc/xen/scripts/vif-route-qubes failed; error detected. backend/vif/51/0/hotplug-status error to xenstore.
Sep 30 16:08:03 proxy2 root[5374]: /etc/xen/scripts/vif-route-qubes: /etc/xen/scripts/vif-route-qubes failed; error detected.

This suggests that vif-route-qubes is failing to set up the interface,
but I am not sure how to fix it.

Any suggestions?

[tetra...@danwin1210.me]

This issue has since resolved itself.

The solution... was to reboot the whole system.