Re: Extended Hitless OSPF Restart

["Manral, Vishwas" <[e-mail]>]

Acee,

I agree to your point, however I guess the draft
http://www.ietf.org/internet-drafts/draft-nguyen-ospf-oob-resync-00.txt
though not a working group item does allow Out of Band resynch, something
like the functionality you talk about below.

Thanks,
Vishwas

-----Original Message-----
From: Acee Lindem [mailto:[e-mail]]
Sent: Thursday, June 27, 2002 3:40 AM
To: [e-mail]
Subject: Re: Extended Hitless OSPF Restart


Daniel Gryniewicz wrote:
>
> Isn't the whole point of a grace period that you want to exceed a router
dead
> interval?  If you are not going to exceed it, you can just do an ISIS
restart,
> which does not need a grace period at all.

The main differenence is that without graceful restart, OSPF offers no
mechanism
for learning the link state database without transitioning out of full state
and
re-originating router/neighbors LSAs, etc.


>
> Daniel
>
> On Wed, 26 Jun 2002 14:14:27 -0700
> Acee Lindem <[e-mail]> wrote:
>
> > Daniel Gryniewicz wrote:
> > >
> > > Hi.
> > >
> > > Could someone please explain to me why this is necessary?  My reading
of
> > > draft-ietf-ospf-hitless-restart-02 indicates that an implementation
should
> > > *not* exit helper status because a router dead interval expired.
Please
> > > enlighten me.
> >
> > This not what I've implemented. A router acting as a helper will exit
> > helper mode when:
> >
> >     1. The inactivity timer expires.
> >     2. The interface goes down (which will also cause an LSA change).
> However,>        I've made it a configurable option whether or not a given
> router acting>        as a helper exits graceful restart when there is a
> change to an LSA which>        will be flooded to the restarting router.
> >     3. Certain sequence mismatch conditions (but not the obvious ones
that
> occur>        naturally during graceful restart).
> >
> > I'd be interested in what others have implemented.
> >
> > Thanks,
> > Acee
> >
> >
> > >
> > > Daniel
> > >
> > > On Tue, 25 Jun 2002 19:51:32 -0700
> > > Acee Lindem <[e-mail]> wrote:
> > >
> > > > FYI - Ultimately, this would be an informational RFC or better yet
> > > > folded into the base "OSPF Hitless Restart" specification (although
> > > > this has not been discussed as of yet).
> > > >
> > > > Thanks,
> > > > Acee