OSPF performance/SPF calculations

[Joakim Tjernlund]

Ondrej Zajicek <santiago at crfreenet.org> wrote on 2010/04/23 10:32:06:
> > > The development state of Quagga is sad. Do you implement it in a different
> > > way than in BIRD? I wonder whether there is any other possible way to get
> > > next hop address for unnumbered ptp links than from source address
> > > of HELLO packet.
> >
> > Yep, now it gets tricky. It took me quite some time to figure out what to
> > do. The secret is that you never use search for the interface using IP addresses
> > in the LSA's.
>
> That we never done for PTP ifaces.
>
> > Instead you record what interface created what entry in in your
> > own Router LSA. Based on the position of on entry in your own router
> > LSA you can lookup the interface that created that entry. Once
> > you know the interface, the reset is easy.
>
> Yes, i got the idea. Our algorithm (for PTP) is to search for a ptp
> iface with a full neighbor with given Router ID and choose the cheapest
> one. This would lead to the same results as your idea, but a slightly
> less efficient, but probably not important unless you have a hundreds
> of PTP ifaces on a router.

I got a lot of PtP I/Fs(some 20-30) :)

But this won't fix multiple ptp I/Fs between the same two routes and
I don't think it will work if one end is unnumbered and the other one is not.

As you can see from the patches I sent earlier there is a simple
impl. and a more complicated impl.

  Jocke