Feature request: CARP awareness in BIRD?

[Thomas Steen Rasmussen]

On 6/2/22 7:04 PM, Marek Zarychta wrote:
> W dniu 2.06.2022 o 16:16, Thomas Steen Rasmussen pisze:
>> Hello :)
>>
>> I am using BIRD on FreeBSD and it is working okay, apart from missing 
>> CARP awareness. I am wondering if anyone knows if work has been done 
>> in this area already?
> 
> You can solve this problem by creating two configs for BIRD and 
> deploying devd(8) with simple helper shell script to trigger 
> reconfiguration of BIRD when carp switches from BACKUP to MASTER or from 
> MASTER to BACKUP. I have had some WiP scripts, but abandoned the idea 
> since it would require doubling active BGP sessions for each peer what 
> would be probably waste of resources and not acceptable in some cases.
> 

Hello,

Thank you for your response! Devd "config mangling" is indeed what I am 
doing now. But it is far from elegant, and it still has quite some rough 
edges and corner-cases making it a suboptimal solution. In other words I 
consider it a hack/workaround I would love to get rid of - hence this 
thread.

What would it require to teach BIRD about CARP states? I can think of 
two things needed, without knowing anything about BIRD internals:

- BIRD has to understand that an IP can be configured on an interface, 
but still not be in a usable state. A new flag on each IP perhaps?
- BIRD has to be informed/learn about the current VHID state on each 
interface, so it can change the internal state of each IP based on VHID 
MASTER/BACKUP

But I don't know the scope of this job, and I am curious to know if such 
a change would be accepted into BIRD upstream?

Thanks!

Best regards,

Thomas Steen Rasmussen