Comment 1 for bug 994471

What version of code are you running?

Running trunk in devstack, I am seeing the file get correctly populated:

nicira@precise1:~/devstack$ cat /opt/stack/nova/networks/nova-gw-fb9746ac-7c.conf
fa:16:3e:17:cb:10,host-10.0.0.2.novalocal,10.0.0.2
fa:16:3e:36:37:49,host-10.0.0.3.novalocal,10.0.0.3

Looks like your conf files are in another directory, so perhaps you're running from packages?