Subject: Re: OSPFv3 Applications Support

From: "Naidu, Venkata" <[email-masked]>
Date: Wed, 12 Mar 2003 16:52:58 -0500

Dave,

-> Code commonality is entirely orthogonal to the issue of whether you
-> run integrated or SIN.

  I knew someone is going to say this ;-)

-> SIN is usually going to be more flexible, as you can have totally
-> independent configurations and topologies.

  Dave, then I prefer to run OSPFv3 for IPv6 and IPv4 in
  a SIN basis. What I am trying to make a point is totally
  from an evolution perspective (hope you understand):

  IPv6 evolution from IPv4 is going to restrict OSPFv3 deployment
  in IPv6 only environment. Success of IPv6 is orthogonal
  to OSPFv3 deployment for me (I don't know why we are
  trying to bind IPv6 success with OSPFv3).

  OSPFv2 is new version which is not compatible with OSPFv1
  (unlike other protocols where IGMPv3 is compatible
  with IGMPv2/1). In the same way, OSPFv3 is another refined
  version of the OSPF protocol.

  Some one made a point that OSPFv2 is refined over years.
  Yes. But all those refinements are already in OSPFv3
  (RFC2328 < RFC2470). More over, OSPFv3 has more
  refinements which can't be put into OSPFv2 because of
  backward compatibility issues (just like OSPFv2 is created
  when there is no way to make OSPFv1 work)

-> Customer acceptance and compatibility is a biggie; until
-> everybody has
-> a *stable* OSPFv3, nobody in their right mind will bet their IPv4
-> network on it (and can't in any case if the code's not there.)

  IMHO, OSPFv3 is going to perform at least (in the worst case)
  as good as OSPFv2 in IPv4 environments. It is just a matter
  of proving things to SPs - getting their trust/hope. It is
  all chicken and egg problem (where to start the chain reaction).
  Other than that, I don't see any technical argument.
  Do you think that OSPFv3 is going to perform poorly on
  IPv4 networks?!?

Venkata.

---

From: Dave Katz <[email-masked]>
Date: Wed, 12 Mar 2003 14:26:02 -0800

v6 success is bound to *some* IGP;  most of our customers are asking
for OSPFv3, even though v6 for ISIS is far less risky (as far as
the volume of new code goes.)  The ISPs that run ISIS for v4 will
probably run it for v6 as well, but the rest of the world will
clamor for OSPF.  The fates are very much intertwined.

That's like saying a Mack truck is a "refined version" of a Model T.
;-) The v1/v2 issue is ancient history--the number of folks that had
to make that transition was vanishingly small by modern standards, and
the environment was *very* different in those days (nobody actually
expected the network to stay up.)  I'm not sure what your point is.

I'm actually agnostic about whether someone should run an integrated
v3 or separate v2/v3.  The interesting issue is whether or not these
"refinements" are important enough for people to want to switch
protocols.  (This is, of course, a minor version of the bigger
question, whether people will want to switch to v6 at all, but I'll
stay out of that gunfight.)

I'm sure OSPFv3 as a protocol is just fine and dandy and will perform
wonderfully.  However, the number of really good OSPFv2
implementations is vanishingly small, even after the better part of 15
years, and I can pretty much guarantee that OSPFv3 implementations are
not going to be better than the existing OSPFv2 implementations from
the same vendors.  The customers generally don't change things unless
there is a compelling economic need to do so.

My guess is that, if v3 does end up supporting both v4 and v6, most
customers will stick with v2 until they're really sure that the v3
implementations are solid, and may never switch unless there's something
they really need that v2 doesn't do for v4.  (Lots of v's.  ;-) )

---

From: Quaizar Vohra <[email-masked]>
Date: Wed, 12 Mar 2003 14:31:05 -0800

>   when there is no way to make OSPFv1 work)

I think you are twisting my argument. I said that the
OSPFv2 implementation took several years refining. Note
the word IMPLEMENTATION in there. Refining the ietf spec
itself is no doubt itself an issue.

 >   Do you think that OSPFv3 is going to perform poorly on

I don't think its a question of whether OSPFv3 will perform better or
not. It will, as other protocols have, take its time refining the spec
followed by ironing out all the implementation issues.  You can't
claim something is better than the other until its implemented and
deployed.

Technical argument or should I say motive is needed when you
try to solve a problem. I don't see a problem yet.

Quaizar