recent change to ifconfig breaks OpenVPN?

[Li, Qing]

> 
> I did at least have time to figure out the commit that changed it:
> 195914
> 
> > Author: qingli
> > Date: Mon Jul 27 17:08:06 2009
> > New Revision: 195914
> > URL: http://svn.freebsd.org/changeset/base/195914
> >
> > Log:
> >  This patch does the following:
> >
> >      - Allow loopback route to be installed for address assigned to
> >        interface of IFF_POINTOPOINT type.
> >      - Install loopback route for an IPv4 interface addreess when
the
> >        "useloopback" sysctl variable is enabled. Similarly, install
> >        loopback route for an IPv6 interface address when the sysctl
> > variable
> >        "nd6_useloopback" is enabled. Deleting loopback routes for
> > interface
> >        addresses is unconditional in case these sysctl variables
were
> >        disabled after an interface address has been assigned.
> 

In 7.x and prior releases, the local-ip of the PPP links 
(e.g. tun, gif, gre) is not reachable within that system. I don't 
know if that really make sense. 

The Host Requirements RFC-1122, Section 3.3.4 on Local Multihoming seems

to suggest the local-ip of a PPP link is not irrelevant as was treated
by 
the implementation.

In r195914, I added a loopback route for the local-ip of the local end
of a PPP link to make the local-ip reachable within the system.

Since a host route is installed for the remote end, the installation
of the loopback route for the local-ip (that is the same IP as the
remote end)
fails. As Julian pointed out, the configuration from OpenVPN seems
erroneous.

At this point I don't believe there is anything I need to fix but
comments are welcomed.

> 
> Setting net.link.ether.inet.useloopback=0 does not restore the
> previous behavior.
> 

I also verified setting (useloopback=0)  * does * restore to the
previous 
behavior.

-- Qing