Filter based on BGP protocol status ...

[Xavier Trilla]

>More simply, you can add a community on the non-ddos-protected provider to make them lower the localpref to peer routes, and stop the prepend.

We tried, but some providers basically ignore everything if you have a direct connection with them. They just forward you the traffic despite prepending or localpref.

Thanks!
Xavier.

-----Mensaje original-----
De: Bird-users <bird-users-bounces at network.cz> En nombre de Alarig Le Lay
Enviado el: jueves, 24 de marzo de 2022 13:43
Para: bird-users at network.cz
Asunto: Re: Filter based on BGP protocol status ...

On Thu 24 Mar 2022 07:43:03 GMT, Douglas Fischer wrote:
> I know that it is not the focus of your question, and also is not the 
> focus on this mail list, but...
> 
> To that kind of automation, the best BGP engine you will find is 
> ExaBGP. It is not focuses in been in compliance with all the concepts 
> of a routing system itself. It's focus is exactly automations using API.
> 
> The scenario you described triggered-me something like a Zabbix 
> looking to the status of BGP sessions of bird, and based on that doing 
> API queries to a ExaBGP that is a iBGP peer of Bird.
> 
> This model is used on many tools focused in anomaly detection for 
> triggering DDoS mitigation.
> 
> 
> But, if your intention is a much simpler scenario, the suggestion 
> Maria made is the most common!
> You can used also some BGP communities(if your upstream supports it) 
> for no-export for some prefixes... Sometimes it helps.

More simply, you can add a community on the non-ddos-protected provider to make them lower the localpref to peer routes, and stop the prepend.

> Em qua., 23 de mar. de 2022 12:10, Xavier Trilla 
> <xavier.trilla at clouding.io>
> escreveu:
> 
> > Hi,
> >
> >
> >
> > I’m quite sure this cannot be done, but I also know there is a lot 
> > of BIRD I still don’t know, so here it goes:
> >
> >
> >
> > Is there any way to filter a export route based on another BGP 
> > session status?
> >
> >
> >
> > For the sake of simplicity let’s say we have just two providers A 
> > and B, and I only want to export some specific routes to B when A is down.
> >
> >
> >
> > I can do it externally with a quite simple script (For example: 
> > Check if the provider is down via CLI and if it’s down insert the 
> > routes I want to export to a kernel table and export that to 
> > provider B) but it would be nice if I could do it directly in Bird.
> >
> >
> >
> > I’ve been scratching my head around this, but unless there is 
> > something like if proto.A == down on the filters I don’t really see 
> > how to do it (Or maybe some way to raise a global flag based on if 
> > I’m receiving routes via provider B, but I don’t think that can’t be 
> > done either.)
> >
> >
> >
> > Thanks for your time!
> >
> > Xavier
> >
> >
> >