On 18/03/10 07:52 AM, Sean Boudreau wrote:
> On Wed, Mar 17, 2010 at 09:40:03PM -0400, Karim Mouline wrote:
>    
>> A high profile customer asked:
>>
>> "
>> Is  there a way in QNX Neutrino  to support Virtual IP capability. This allows to set up 2 machine nodes such that 
they would work as a redundant pair. With single virtual IP which will be used by external network devices to 
communicate to that pair. At any time only one ("active") node will owe this IP address and external network devices 
will be using it to communicate to  "active" node. Example of such mechanism is provided by in Linux VRRP RFC 3768, 
Keepalived (2003), HealthChecking for LVS&  High Availability, http://www.keepalived.org/
>> "
>>      
> In the BSD world the equivalent is CARP.  We don't currently have this
> enabled.
>
>    
Indeed CARP would be the best way to do this. I don't have much 
experience with it, but as I understand it it is better because it's 
supposedly unencumbered and has security built in. It is also integrated 
with the stack.

I have had more exposure to VRRP and I believe VRRP can be implemented 
as a daemon using sockets and BPF. It may be tricky to do "accept mode", 
but the core VRRP functionality would be easier.

If the customer is really interested in a solution in this area, please 
ask them to request it and maybe it can get done. We've had interest in 
CARP before but AFAICT it has only made it onto the "nice to have" list.

Cheers!
/P