Re: FW: Last Call: Detecting Inactive Neighbors over OSPF Demand

[Abhay Roy <[e-mail]>]

Mitchell,

The important point to note here is that: If the originator is
'reachable', DoNotAge LSA's can stay forever.

Regards,
-Roy-

On 05/30/03-0700 at 12:20am, Erblichs writes:

> Lets cover two stones with one throw..
>
>         Lets try part of this again..
>
>         In the 1793 RFC which deals with demand circuits,
>         there is a 2.3 - 2) section that mentions MaxAge
>         seconds, aka 3600 seconds or 1 hr.
>
> To ensure that these LSAs are eventually
>       flushed from the routing domain, and that the size of the link
>       state database doesn't grow without bound, routers are required to
>       flush a DoNotAge LSA if BOTH of the following conditions are met:
>
> (2) The originator of the LSA has been unreachable (according to
>     the routing calculations specified by Section 16 of [1]) for
>             at least MaxAge seconds.
>
>         If probe exceeds 1 hr then LSAs are most likely
>         dropped and LSAs need to be originated. Thus, tell
>         me why you would want to allow LSAs to be forced
>         to be re-originated in favor of a longer probe.
>
>         I also think you may get a dead nbr, but that is
>         a different discussion point..
>
>         Mitchell Erblich
>         Sr Software Engineer
>         ---------------------
>
>
> Mitchell,
>
> In case of 'always up' DC links, it does turn out to be periodic
> probing. But in case of 'on demand' DC links, (if there is no data
> traffic) it's of no use to bring up the link just to send probes.
> So it makes sense to piggy back this event on the link coming up
> event, and keep doing it periodically till the time line remains
> up (due to data traffic).
>
> Regards,
> -Roy-
>
>
>
> Abhay Roy wrote:
> >
> > Mitchell,
> >
> > Why it MUST not exceed 1hr? Today it's infinity, so in theory any
> > interval (including absurdly high ones) should be allowed.
> >
> > Regards,
> > -Roy-
> >
> > On 05/28/03-0700 at 1:06pm, Erblichs writes:
> >
> > > Sorry group,
> > >
> > >         I forgot..
> > >
> > >         E) If ..ProbeInterval is kept, its max value MUST not exceed
> > >            1 hr..
> > >
> > >         I think this follows that if we haven't heard from our
> > >         nbr in 1 hr "he" is considered dead.
> > >
> > >         Mitchell Erblich
> > >         -------------------
>