Unnumbered PtP links (Was: Re: OSPF: incorrect path computation for v2.0.5+?)

[Joakim Tjernlund]

On Sat, 2020-05-23 at 18:19 +0200, Ondrej Zajicek wrote:
> On Sat, May 23, 2020 at 03:55:16PM +0000, Joakim Tjernlund wrote:
> > > > I would be glad to hear any comments to this idea or suggestions of other
> > > > ideas how to solve it.
> > 
> > Thinking some more on this ..
> > 
> > The pos method depends only on your own Router LSA.
> > If I recall correctly(mind you, this was a long time ago), the R-LSA only depends
> > on your own interfaces wanting to use OSPF, you could always calculate your own R-LSA
> > before starting any graceful restart(or so I hope) instead of relying on someone else's idea
> > of you own R-LSA(it would be safer to only trust your self).
> 
> Well, the graceful restart is based on idea that your FIB (or Kernel)
> still has previous routing table, so you should not use your current
> adjacency state (as some adjacencies may not be yet established).
> 
> You need to parse your old R-LSA, wait until all adjacencies there
> described are newly established, and then resume normal operation.

To be sure all adjacencies are there you would need to compare it against your own newly
calculated R-LSA?  Once your are "happy", you can continue with you own R-LSA and still
use the pos method.

> 
> Now i am not sure if route recalculation is done during GR, or if the
> R-LSA record matching is necessary just for this parsing, will check
> that.
>