Paths Limit for Multiple Paths in BGP

[Ondrej Zajicek]

On Wed, Oct 02, 2024 at 02:42:00PM +0200, Maria Matejka via Bird-users wrote:
> Hello Donatas!
> 
> On Wed, Oct 02, 2024 at 02:29:40PM +0300, Donatas Abraitis wrote:
> 
> > I hope this is the right place to ask for feature requests.
> 
> Yes, it is!
> 
> > Would you mind adding this [1]draft  to your TODO (/ feature) list?
> 
> After reading the draft, I understand that the actual algorithm on how
> to choose the set of paths to be sent, is outside the scope of the
> document. I consider this a major problem which may lead to hard-to-fix
> long-term traffic loops between differing implementations.

That mostly depends on usage pattern, and if the set of announced paths
contains the best path, then routing loops would be transient, like
if you send just one path.


> There are thoughts on actually implementing this in BIRD. 
> Regarding the current development priorities, this is expected to be
> implemented (if it actually happens) in BIRD 3 only, and only after we
> implement some more structural changes in the route storage. Otherwise,
> this is going to be a performance nightmare.

Well, it is not really much different from 'secondary' option - have some
ordering of available paths, announce the first N paths vs. announce the
first path that pass filters.

-- 
Elen sila lumenn' omentielvo

Ondrej 'Santiago' Zajicek (email: santiago at crfreenet.org)
"To err is human -- to blame it on a computer is even more so."