EVPN static IMET route on Bird 3.3.0

[Maria Matejka]

Hello André,

thank you for checking out our EVPN implementation. If I remember
correctly, we didn't think about injecting totally static information,
and therefore I'm afraid there is no easy way around this for now.
Specifically, it doesn't look possible to me to get an EVPN protocol
without the VXLAN device, as it has to generate FDB records using that
device.

You may try changing the type from T_OPAQUE to T_BYTESTRING in
proto/bgp/attrs.c (and building yourself), that should make it
(for 3.3.0) accessible for setting to custom values by filters.
We didn't do that simply because we want to update the filter language
to systematically support structured data, and this would be yet another
quirk to take care about later and possibly carry forward to far future.

Maybe Ondřej has better ideas later today, let's see.

I hope this helps.  
Happy experimenting!  
Maria

On Thu, May 28, 2026 at 08:57:50AM +0200, André Grüneberg wrote:

> Hi again,
> 
> I have tried a few things and looked at a bit of code.
> 
> By now I learned from documentation that I cannot create a custom attribute
> -- bgp_pmsi_tunnel already exists. And I cannot assign a bytestring -- the
> documentation says it's not accessible in filters. Since the route
> attribute is of T_OPAQUE, I also cannot assign a value in the static route.
> 
> The only place in the code accessing bgp_pmsi_tunnel is in
> evpn_announce_imet(). So it seems I will need a minimal protocol evpn in my
> config. Can I build one without having all the vxlan interfaces?
> Note: I need the router address to be another system.
> 
> Thanks,
> André
> 
> On Wed, 27 May 2026 at 17:12, André Grüneberg <andre.grueneberg at bcix.de>
> wrote:
> 
> > Hi bird users,
> >
> > I am currently experimenting with Bird 3.3.0 and EVPN. I do not need/want
> > a local termination, but want to inject static EVPN routes only.
> >
> > Despite missing documentation (hint!), I found the necessary syntax to
> > define mac-ip and imet routes. I also managed to manually set the required
> > ext communities (tunnel type, MAC mobility, RT) as well as the VNI
> > (mpls_label) in the filter.
> >
> > What remains open is the  bgp_pmsi_tunnel attribute. According to the
> > documentation it's not available in filters.
> >
> > Is there any alternative way to statically set it? Maybe a custom
> > attribute and a binary string?
> >
> > Thanks,
> > André
> >
> > --
> > André Grüneberg, Managing Director
> > andre.grueneberg at bcix.de
> >
> > +49 30 2332195 42
> >
> > BCIX Management GmbH
> > Albrechtstr. 110
> > 12103 Berlin
> > Germany
> >
> > Geschäftsführer/Managing Directors: Jens Lietzmann, André Grüneberg
> > Handelsregister: Amtsgericht Charlottenburg, HRB 143581 B
> >
> 
> 
> -- 
> André Grüneberg, Managing Director
> andre.grueneberg at bcix.de
> +49 30 2332195 42
> 
> BCIX Management GmbH
> Albrechtstr. 110
> 12103 Berlin
> Germany
> 
> Geschäftsführer/Managing Directors: Jens Lietzmann, André Grüneberg
> Handelsregister: Amtsgericht Charlottenburg, HRB 143581 B

-- 
Maria Matejka (she/her) | BIRD Team Leader | CZ.NIC, z.s.p.o.  
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