mpls-new and generate encap mpls route?

[Tim Weippert]

Hi Jan, 

On Wed, Jun 22, 2016 at 04:08:09PM +0200, Jan Matejka wrote:
> Hi!
> 
> > currently i playing with mpls on linux and bird mpls-new branch, as i created an test l3vpn i
> > haven't found a way to configure bird for creating encap mpls routes from bird. MPLS Routes 
> > are generated and successfully installed within the kernel.
> 
> First of all, beware! We have recently found out better way to implement
> that functionality. You should know that this code is work in progress,
> highly experimental and may contain fatal bugs, memory leaks and other
> dangerous features.

Yes, i'm full aware of the risks and potential problems, this is only in my lab environment
so, no harm to productiv environments.

> I'm slowly porting and rebasing this branch ontop "nexthop" branch which
> contains a little rework of the multipath concept in Bird. Please note
> that also the "nexthop" branch is still experimental.

Yes, i see the port to nexthop too, but thought that mpls-new is "more mpls ready" currently.
 
> > Is this not implemented, or did i miss something. I read some of the commits and 
> > thought that the kernel/netlink part can handle this. Additional i don't find a way to define 
> > the used labels, it seems that bird is generating new labels by default with start at 32. Can this be
> > influenced?
> 
> In mpls-new, there is not possible to set the label set used for l3vpn.
> Anyway, we know there should be some config option to influence it.
> 
> On the other hand, the kernel/netlink part should be able to insert both
> IP encap routes and also MPLS routes.

Ok, thanks for the clarification. Yes i see the MPLS Routes from the l3 vpn and thought
if this can be tweaked to create encap routes it may be usefull in an simple PE szenario for
encasulate the IP packet in MPLS.  

> Well, it isn't so easy.

[ ... ]

Thanks for the explanation about MPLS activation on Linux, i currently running an
CE/PE/P construct running with static MPLS Routing/Encapsulations and want try how bird currently
plays with this environment.
 
> You may also need quite a new kernel. In Debian kernel, everything works
> since v4.5, maybe since v4.4, I don't remember it well.

Yes, i use ArchLinux with an 4.4.13 kernel currently.
 
> However, you should read my warning once more. This code is highly
> experimental and may change at all.
> 
> The plan for near future is to release Bird (integrated IPv4 and IPv6)
> with experimental support for labeled BGP in route-reflector mode. We
> may in future, surely not this year, support also MPLS-PE mode.
>
> I hope this explanation puts some light on the problem.

Yes, many thanks for your explanations again. Maybe i can help you with some tests or similar, as i'm interested
in these development. So, i will look in the nexthop branch for your porting :) 

> Thank you for trying our experimental code!

Thanks for providing them :)

cheers, 
tim


-- 
Tim Weippert
http://weiti.org - weiti at weiti.org
GPG Fingerprint - E704 7303 6FF0 8393 ADB1  398E 67F2 94AE 5995 7DD8