Comment 6 for bug 1310852

Regarding the log in the first Matt's comment, I've found the following discrepancy:

The server to which tempest is trying to check the connectivity supposed to have 10.100.0.20 as fixed ip and 172.24.4.61 as floating.
Server output from nova doesn't show that server with fixed ip 10.100.0.20 has floating ip:
http://logs.openstack.org/24/88224/2/check/check-tempest-dsvm-neutron-2/dfb1367/console.html.gz#_2014-04-21_17_12_36_097

In the end of the log file another output from nova could be seen: http://logs.openstack.org/24/88224/2/check/check-tempest-dsvm-neutron-2/dfb1367/console.html.gz#_2014-04-21_17_12_36_564

Here you can see that VM has expected floating ip 172.24.4.61 but fixed ip is different: 10.100.0.18
If you search by 172.24.4.61 you'll see that it was only associated with 10.100.0.18 ever.
I'm not sure I'm interpreting logs correctly, at least it confuses me that logs related to the failing tests show nova output for different servers.

Anyway my conclusion is that there is a discrepancy between fixed/floating ips of the instance and test's expectation.
I was not able to find out the root cause yet.