[Openais] openais netmask and its relationship to how Totem binds to NICs

[Steven Dake]

I have had several questions over the last few days with people using
10.x.x.x networks with openais binding to 127.0.0.1.  So I attempted to
copy their exact configuration and found indeed, things weren't working
as I had expected.

The full description of the relationship of bindnetaddr and netmask can
be found here:

http://www.openais.org/doku.php?id=faq:configure_openais

Essentially the way it works is:

for all interfaces in system
        if bindnetaddr == iface.addr & iface.netmask
                bind to interface


For example:

If the local interface was 10.12.12.93 and the netmask was 255.0.0.0,
Totem would execute the logical operation 10.12.12.93 & 255.0.0.0 and
produce the value 10.0.0.0. This value would be compared against
bindnetaddr and bind Totem to the NIC that matches.

This can cause confusion if netmask is not set properly.

In the example above, if bindnetaddr is 10.12.12.0, the network
interface will never be matched. If bindnetaddr is 10.0.0.0 the
interface will be matched.

A future upcoming patch will modify the man pages and QUICKSTART guide
to explain this behavior.

Regards
-steve