SRv6

Thu Sep 17 15:40:17 UTC 2020

On 17/Sep/20 01:30, Łukasz Bromirski wrote:

> And that’s fine. The fact that some Intellectual Property[1] was created
> by one vendor or another (disclaimer - I work for Cisco) shouldn’t be
> by default something that discredits the idea. And BTW, if You look into
> the history of how SR started, it was close feedback loop with at least
> some of the ISPs wanting to have “easier” and SDN-ish control over the
> network so the blame should be shared :) Having support from other
> vendors was de facto requirement to even think about deploying it widely
> and that's better approach IMHO than “lets patent everything out and
> force everyone into our black-box-architecture that’s best in the world”.
>
> I’m observing the discussions over the last couple of months and
> generally they boil down to “leave us alone, everything sucks, we’ll
> stay with what we have”. And sure, as you indisputably proven during last
> 30 years, running modern ISP network can be done over IP, MPLS, and the
> network can even survive introduction of IPv6. And I get it - vendors
> have generally failed to address your ideas and problems in timely manner,
> and when we did, quality was simply not there. But really, is that all
> what’s interesting in life? I doubt it. Unless the whole point of
> discussing here would be to start from technical topics
> (because of ‘rules’) and end up with everybodys favorite part - beating
> virtual Pinata made to look like representation of most hated
> salesman/vendor. Then sorry, I somehow missed that :)
>
> While I personally find the idea of stacking IPv6 labels gruesome for
> any non-trivial label depth[2] (and I'm really worried about software guys
> coming in from the “mobile app” world soon, and finding out that they can
> create those IPv6 EH stacks easily), going forward we have to think
> about what will keep networks running in for the next 5, 10 or 20 years.
> IPv4 with MPLS+LDP+RSVP-TE will work fine of course, so will SRoMPLS,
> but IPv6 is gaining adoption and need to multiplex/demultiplex more and
> more services and users will only grow. And BTW, MPLS forwarding between
> ASes in the internet is still something that works mainly on slides,
> highly paid consulting “proposals” and of course on the CCIE exam.

I have no problem at all with dreaming up nice fancy features that 
either move the industry forward or just eliminate a great deal of 
personal idleness.

My problem is now using that tech. to force a business model that is no 
longer relevant in these times we live in. And somehow, making that 
tech. complicated enough to justify those business models.

I'm sure the genius engineers that thought up the idea aren't likely the 
suits who decide to monetize said idea in an unreasonable manner. I'm 
even more sure that if you had both sitting in the same room, they'd 
never converge on a "go to market" strategy.

So no, nothing against technology. Totally against it being commercially 
weaponized.

> On the other side, there’s Elon Musk moving us to Mars, wretched IoT
> world with “build, sell and forget" mentality w/r to firmware and good
> network stacks. And yet only 59% people around the world today have internet
> access. At least good portion of that heavily filtered one by the way.

That Tesla Powerwall does look awfully sexy. But no way I'm dishing out 
all that dosh for a measly 13kWh of storage just so it can shutdown 
after 48hrs of no Internet. For that price, there are many places that I 
can get 35kWh from, and not have to be concerned about being spied on 
for years just so the Powerwall can make it to the "Guaranteed for 8 
years" finish line.

As you can tell, I always find the dark lining in the vendor sales 
pitches :-).

> IPv6 seems to be good plan forward (and would potentially unify
> architecture of normal routing and overlay routing with SRv6), even
> if things like MPLSoUDP or GRE would really solve everything if pushed
> with enough force[3] ;) It’s worth observing, that from this perspective
> IPinIP would be as good as SRv6 if everyone would agree 20 years ago that
> source routing is acceptable. LDP or RSVP-TE would never gain any usage
> and maybe we wouldn’t learn lesson or two. BTW, we tried to somehow get
> back to this simplification with LISP[4], and in the long run it seems
> overloading address semantics is not something that is happily accepted
> everywhere, and it doesn’t matter if that's IPv4 or IPv6.
>
> So much hated middleboxes will also adopt faster to IPv6, as adopting MPLS
> data plane after those 20 years on firewalls, load balancers and what-you
> looks kind of dissapointingly. And if we are talking about network
> functions - I believe it’s more important right now to agree on one way
> of doing service chaining, than discussing SR or SRv6 as evil seed created
> to conquer the world.
>
> SR takes out state out, and SRv6 has the same address format on the
> outside as well as inside. You can happily run it with both data planes,
> and while today maybe you can’t provide migration of ALL services,
> SR+IGP quite nicely interworks with MPLS+LDP.
>
> Will HW evolve? It has to anyway, no previous change was done day one
> and 128 bits times 5 or 8 or 12 seems horrible only today. Over the
> years, people got used to bigger horrors ;)

We all agree that if there is something better than MPLS, let's find it. 
It's just that new solutions ought to make things (look) simpler, not 
(look) more complex.

Mark.