Comment 3 for bug 1398566

Here, in general form, are the steps used to reproduce this issue as demonstrated in the video:

1. simulate high agent load by changing report_interval to 1
2. simulate startup processing load by putting a sleep immediately after the line containing:
        ext_mgr = extensions.PluginAwareExtensionManager.get_instance()
   in neutron/api/v2/router.py
3. stop agents
4. stop neutron server
5. start agents
6. start neutron server

run nova network-list until REST API starts responding. Networks with router:external=True that should be visible due to the neutron FieldCheck on the external network extension do not succeed. Consequence is these networks are hidden from the user.