This bug's parent bug was for the Release Notes component. Note Bob's final comment: "this information needs to be incorporated into the Getting Started Guide for future releases." Hence this new clone.
The para covering this in Rel Notes is the para starting: "Two different mechanisms are available for connecting a quantum-l3-agent to an external network." followed by a quite extended set of commands. This should be able to be moved into GSG as well, probably under "12.5 Installing OpenStack Networking Agents".
*** This bug has been marked as a duplicate of bug 967965 ***
Removing external tracker bug with the id 'https://bugs.launchpad.net/quantum/+bug/1056437' as it is not valid for this tracker