Re: [OSPF] OSPFv3 Extended LSAs TLV-level "disposition-if-unsupporetd indicator"?

["A. Przygienda" <[e-mail]>]

On 08/06/2013 03:49 PM, David Lamparter wrote:
> Hi ospf WG,
>
>
> looking at the Extended LSA draft from the various use cases, I believe
> it would be advantageous to repurpose the topmost two bits of the TLV
> type to indicate what should happen if the TLV is not supported by a
> router.  I'm thinking of 3-4 possible handlings:
> ...
>
>
> -David
>

an impressively deep rathole. Games like that CAN be played (actually,
that's why
things like MT-ISIS was possible at all) _BUT_ a closed proof is needed
that ignoring
certain LSAs by certain routers will _NOT_ lead to routing loops (in
hop-by-hop routing)
since routers hold now for their SPFs different LSDBs.


The theory (yes, it's not light bedtime reading) can be found in

http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=749255&url=http%3A%2F%2Fieeexplore.ieee.org%2Fiel4%2F6063%2F16198%2F00749255.pdf%3Farnumber%3D749255

and that should also enlighten why the concept of 'topology' as in
mathematical
'topology' plays such a strong role.

I would simplify here however & double Russ's suggestion
on wanting a use-case for the goodies proposed first

--- tony