Carp Suppression

[Josh Kayse]

On 6/15/05, Gleb Smirnoff <glebius at freebsd.org> wrote:
<snip> 
> AFAIU, you use PLIP line as some flag that triggers suppression. If
> slave "sees" master via PLIP, it keeps itself in slave mode. May be
> I don't understand you right.
> 
> Although the idea is not officially supported, it is interesting. Can you
> please draw your setup, since I don't understand it clearly?
> 
            __________
em0      |                |em1
------------|     FW1    |-----------
            |_________|
   xl0(carp0)|     | plip0(carp1)
            ___|___|___
em0     |                 | em1
-----------|     FW2     |----------
           |__________|


Bridging is done through em0/em1 which are both monitored by ifstated
for link state only (backported patch from HEAD).

When one of the bridging ports is disconnected, ifstaded changes the
advskew of carp0 and carp1 to 254 so that the carp interfaces
failover.

When ifstated see the carp interfaces as BOTH master, the slave
firewall takes over bridging.

This gives us redundant firewalls, with redundant heartbeat connections.

> Bringing link state support for p2p interfaces is a TODO, although
> CARP is not going to be supported on p2p interfaces officially.
> 
> J> I will refrain from submitting any code to the community in the future.
> 
> Why?
I was just grumpy, we had just expanded server room and everything
broke, etc etc.  Don't mind me at all.

If you have any other questions, just let me know.

PS.  I stink at ascii drawings.

-- 
Joshua Kayse
Computer Engineering