Support using floating IP to connect internal subnets in different address scopes

I can help review this as long at the fix gets up soon. It'd be nice to close this little hole with floating IPs before the Mitaka release. We should be sure that we have good testing around the use cases that we know work already so that we do not regress in trying to fix this issue.

Fix proposed to branch: master
Review: https://review.openstack.org/283134

Related fix proposed to branch: master
Review: https://review.openstack.org/287040

Reviewed: https://review.openstack.org/283134
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=c7e972ce4a5d61cfcdff5b2fc4ba62a94905003a
Submitter: Jenkins
Branch: master

commit c7e972ce4a5d61cfcdff5b2fc4ba62a94905003a
Author: Hong Hui Xiao <email address hidden>
Date: Wed Mar 2 03:12:38 2016 -0500

    Use floating IP to connect different address scopes

    Currently, floating ip could be used to connect internal subnet and external
    subnet in different address scopes. But the internal subnets that are in the
    same address scope of external network are isolated. This is diagramed as
    follow:
    +---------------------+ +------------------------+
    | address scope 1 | | address scope 2 |
    | | | |
    | +----------------+ | | +---+----------+-+ |
    | |internal network| | | |external network| |
    | +------------^---+ | | +-------^--------+ |
    | | | | | |
    | +-------+--+ | | +-------+----+ |
    | |fixed ip A+-------------^+floatingip B| |
    | +----------+ | | +------------+ |
    +---------------------+ | |
                                  | +--------+ +--------+ |
                                  | |internal| |internal| |
                                  | +-----+--+ +----+---+ |
                                  +------------------------+

    This patch will make the fixed ip A be able to connect internal networks in
    address scope2. And internal networks in address scope2 are able to connect
    fixed ip A by visiting floating ip B.

    Change-Id: If3b0b49a994e8c604809e524dca6f4afe5b626f3
    Closes-Bug: #1543885

Related fix proposed to branch: master
Review: https://review.openstack.org/289794

This issue was fixed in the openstack/neutron 8.0.0.0rc1 release candidate.

Change abandoned by Armando Migliaccio (<email address hidden>) on branch: master
Review: https://review.openstack.org/287040
Reason: This review is > 4 weeks without comment, and failed Jenkins the last time it was checked. We are abandoning this for now. Feel free to reactivate the review by pressing the restore button and leaving a 'recheck' comment to get fresh test results.

Reviewed: https://review.openstack.org/289794
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=36893a55bd4c3261896f0775556c515029189efd
Submitter: Jenkins
Branch: master

commit 36893a55bd4c3261896f0775556c515029189efd
Author: Hong Hui Xiao <email address hidden>
Date: Tue Mar 8 03:52:05 2016 -0500

    Add devref for supporting use floatingip cross scopes

    [1] has been merged for supporting use floating IP to cross scopes.
    The devref should be updated for it, due to the discussion in [1].

    [1] https://review.openstack.org/#/c/283134/

    Change-Id: I5c330ba5d5446ec985b628d8bc3b37d65fa7d53d
    Related-Bug: #1543885

Change abandoned by Armando Migliaccio (<email address hidden>) on branch: master
Review: https://review.openstack.org/287040
Reason: This review is > 4 weeks without comment, and failed Jenkins the last time it was checked. We are abandoning this for now. Feel free to reactivate the review by pressing the restore button and leaving a 'recheck' comment to get fresh test results.