Mailing List Archive

Hi,

On Wed, Jun 10, 2020 at 07:19:18PM +0200, Mark Tinka wrote:
> Just want to sample the room and find out if anyone here - especially
> those running an LDP-based BGPv4-free core (or something close to it) -
> would be interested in LDPv6, in order to achieve the same for BGPv6?
>
> A discussion I've been having with Cisco on the matter is that they do
> not "see any demand" for LDPv6, and thus, won't develop it (on IOS XE).
> Meanwhile, it is actively developed, supported and maintained on IOS XR
> since 5.3.0, with new features being added to it as currently as 7.1.1.

To be honest, I do not think we're going to buy any IOS XE gear in the
foreseeable future. But if we did, LDPv6 would be nice to have - to get
rid of IPv4 in the backbone network.

We do not intend to run SRv6 any time soon.

gert
--
"If was one thing all people took for granted, was conviction that if you
feed honest figures into a computer, honest figures come out. Never doubted
it myself till I met a computer with a sense of humor."
Robert A. Heinlein, The Moon is a Harsh Mistress

Gert Doering - Munich, Germany gert@greenie.muc.de

I would take either LDPv6 or SRv6 - but also need L3VPN (and now EVPN)
re-wired to use IPv6 NH.

I have requested LDPv6 and SRv6 many times from Cisco to migrate the
routing control plane from IPv4 to IPv6

I have lots of IPv6 address space. I don't have a lot of IPv4
address space. RFC1918 is not as big as it seems. Apparently this is hard
to grasp...

(This is primarily IOS-XE - can't afford the IOS-XR supercars)

On Wed, Jun 10, 2020 at 1:20 PM Mark Tinka <mark.tinka@seacom.mu> wrote:

> Hi all.
>
> Just want to sample the room and find out if anyone here - especially
> those running an LDP-based BGPv4-free core (or something close to it) -
> would be interested in LDPv6, in order to achieve the same for BGPv6?
>
> A discussion I've been having with Cisco on the matter is that they do not
> "see any demand" for LDPv6, and thus, won't develop it (on IOS XE).
> Meanwhile, it is actively developed, supported and maintained on IOS XR
> since 5.3.0, with new features being added to it as currently as 7.1.1.
>
> Needless to say, a bunch of other vendors have been supporting it for a
> while now - Juniper, Nokia/ALU, Huawei, even HP.
>
> IOS XR supporting LDPv6 notwithstanding, Cisco's argument is that "the
> world" is heavily focused on deploying SRv6 (Segment Routing). While I know
> of one or two questionable deployments, I'm not entirely sure much of the
> world is clamouring to deploy SR, based on all the polls we've done at
> various NOG meetings and within the general list-based operator community
>
> So I just wanted to hear from this operator community on whether you would
> be interested in having LDPv6 support to go alongside your LDPv4
> deployments, especially if you run native dual-stack backbones. Or if your
> focus is totally on SRv6. Or if you don't care either way :-). Thanks.
>
> Mark.
>


--
Tim:>
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On 10/Jun/20 20:10, Gert Doering wrote:

> To be honest, I do not think we're going to buy any IOS XE gear in the
> foreseeable future. But if we did, LDPv6 would be nice to have - to get
> rid of IPv4 in the backbone network.

We have LDPv6 working beautifully between IOS XR (6.4.2) and Junos
(17.4). But we can't make the core BGPv6-free because downstream
ASR1000's and ASR920's don't have it.

So if you don't have IOS XE today, but have the others, then you're good
to go :-).

Nobody is going to demand LDPv6, because it's not about LDPv6... it's
about IPv6, and wanting IPv4 parity. But, guess that doesn't much a
business case write.


>
> We do not intend to run SRv6 any time soon.

As I thought :-).

Mark.

I'm pretty sure that one or more of Mark, Gert or Tim are thinking
SR/MPLS IPv6 when they say SRv6?

No one in their right minds thinks SRv6 is a good idea, terrible snake
oil and waste of NRE. SR/MPLS IPv6 of course is terrific.

LDPv6 and SRv6 seem like an odd couple, LDPv6 SR/MPLS IPv6 seem far
more reasonable couple to choose from. I have my favorite.


On Wed, 10 Jun 2020 at 21:32, Tim Durack <tdurack@gmail.com> wrote:
>
> I would take either LDPv6 or SRv6 - but also need L3VPN (and now EVPN) re-wired to use IPv6 NH.
>
> I have requested LDPv6 and SRv6 many times from Cisco to migrate the routing control plane from IPv4 to IPv6
>
> I have lots of IPv6 address space. I don't have a lot of IPv4 address space. RFC1918 is not as big as it seems. Apparently this is hard to grasp...
>
> (This is primarily IOS-XE - can't afford the IOS-XR supercars)
>
> On Wed, Jun 10, 2020 at 1:20 PM Mark Tinka <mark.tinka@seacom.mu> wrote:
>>
>> Hi all.
>>
>> Just want to sample the room and find out if anyone here - especially those running an LDP-based BGPv4-free core (or something close to it) - would be interested in LDPv6, in order to achieve the same for BGPv6?
>>
>> A discussion I've been having with Cisco on the matter is that they do not "see any demand" for LDPv6, and thus, won't develop it (on IOS XE). Meanwhile, it is actively developed, supported and maintained on IOS XR since 5.3.0, with new features being added to it as currently as 7.1.1.
>>
>> Needless to say, a bunch of other vendors have been supporting it for a while now - Juniper, Nokia/ALU, Huawei, even HP.
>>
>> IOS XR supporting LDPv6 notwithstanding, Cisco's argument is that "the world" is heavily focused on deploying SRv6 (Segment Routing). While I know of one or two questionable deployments, I'm not entirely sure much of the world is clamouring to deploy SR, based on all the polls we've done at various NOG meetings and within the general list-based operator community
>>
>> So I just wanted to hear from this operator community on whether you would be interested in having LDPv6 support to go alongside your LDPv4 deployments, especially if you run native dual-stack backbones. Or if your focus is totally on SRv6. Or if you don't care either way :-). Thanks.
>>
>> Mark.
>
>
>
> --
> Tim:>



--
++ytti
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On 10/Jun/20 20:29, Tim Durack wrote:
> I would take either LDPv6 or SRv6 - but also need L3VPN (and now EVPN)
> re-wired to use IPv6 NH.

At the moment, LDPv6 doesn't have what I call "service" support, i.e.,
l3vpn's, l2vpn's, MPLSv6-TE, mLDP, CsC, e.t.c. To be honest, I don't
mind those so much on my end because you can still run a BGP-free core
and still deliver those services.

Granted, if your goal is a single-stack MPLS-based IPv6 network, then
yes, it would be good for LDPv6 to support the "services".

But if it's just vanilla MPLSv6 switching you're after, then LDPv6 will
do just fine.


>
> I have requested LDPv6 and SRv6 many times from Cisco to migrate the
> routing control plane from IPv4 to IPv6

Well, according to them, SRv6 is winning customers over, and nobody
wants LDPv6. Then again, they have LDPv6 in IOS XR; figures.


>
> I have lots of IPv6 address space. I don't have a lot of IPv4
> address space. RFC1918 is not as big as it seems. Apparently this is
> hard to grasp...
>
> (This is primarily IOS-XE - can't afford the IOS-XR supercars)

LDPv6 must be a business case :-). Well, wonder how they sell so many
CGN's, then :-).

Mark.

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Hi,

On Wed, Jun 10, 2020 at 08:45:31PM +0200, Mark Tinka wrote:
> On 10/Jun/20 20:10, Gert Doering wrote:
>
> > To be honest, I do not think we're going to buy any IOS XE gear in the
> > foreseeable future. But if we did, LDPv6 would be nice to have - to get
> > rid of IPv4 in the backbone network.
>
> We have LDPv6 working beautifully between IOS XR (6.4.2) and Junos
> (17.4). But we can't make the core BGPv6-free because downstream
> ASR1000's and ASR920's don't have it.
>
> So if you don't have IOS XE today, but have the others, then you're good
> to go :-).

We do have IOS XEs today (ASR920), and based on that, we're not going
to buy new IOS XE devices any time soon.

The amount of... strangeness... that this BU considers acceptable
is... not.

gert

--
"If was one thing all people took for granted, was conviction that if you
feed honest figures into a computer, honest figures come out. Never doubted
it myself till I met a computer with a sense of humor."
Robert A. Heinlein, The Moon is a Harsh Mistress

Gert Doering - Munich, Germany gert@greenie.muc.de

Hi,

On Wed, Jun 10, 2020 at 09:45:55PM +0300, Saku Ytti wrote:
> I'm pretty sure that one or more of Mark, Gert or Tim are thinking
> SR/MPLS IPv6 when they say SRv6?
>
> No one in their right minds thinks SRv6 is a good idea, terrible snake
> oil and waste of NRE. SR/MPLS IPv6 of course is terrific.
>
> LDPv6 and SRv6 seem like an odd couple, LDPv6 SR/MPLS IPv6 seem far
> more reasonable couple to choose from. I have my favorite.

Oh. Indeed, sorry for being unclear here.

SR/MPLS sounds like a good idea (reducing label state).

SR/IPv6 does not sound convincing.

gert
--
"If was one thing all people took for granted, was conviction that if you
feed honest figures into a computer, honest figures come out. Never doubted
it myself till I met a computer with a sense of humor."
Robert A. Heinlein, The Moon is a Harsh Mistress

Gert Doering - Munich, Germany gert@greenie.muc.de

Ah yes, I would say LDPv6 and/or SR/MPLS IPv6. SRv6 reads like a science
project.

Either way, I would like to achieve a full IPv6 control plane.


On Wed, Jun 10, 2020 at 2:46 PM Saku Ytti <saku@ytti.fi> wrote:

> I'm pretty sure that one or more of Mark, Gert or Tim are thinking
> SR/MPLS IPv6 when they say SRv6?
>
> No one in their right minds thinks SRv6 is a good idea, terrible snake
> oil and waste of NRE. SR/MPLS IPv6 of course is terrific.
>
> LDPv6 and SRv6 seem like an odd couple, LDPv6 SR/MPLS IPv6 seem far
> more reasonable couple to choose from. I have my favorite.
>
>
> On Wed, 10 Jun 2020 at 21:32, Tim Durack <tdurack@gmail.com> wrote:
> >
> > I would take either LDPv6 or SRv6 - but also need L3VPN (and now EVPN)
> re-wired to use IPv6 NH.
> >
> > I have requested LDPv6 and SRv6 many times from Cisco to migrate the
> routing control plane from IPv4 to IPv6
> >
> > I have lots of IPv6 address space. I don't have a lot of IPv4 address
> space. RFC1918 is not as big as it seems. Apparently this is hard to
> grasp...
> >
> > (This is primarily IOS-XE - can't afford the IOS-XR supercars)
> >
> > On Wed, Jun 10, 2020 at 1:20 PM Mark Tinka <mark.tinka@seacom.mu> wrote:
> >>
> >> Hi all.
> >>
> >> Just want to sample the room and find out if anyone here - especially
> those running an LDP-based BGPv4-free core (or something close to it) -
> would be interested in LDPv6, in order to achieve the same for BGPv6?
> >>
> >> A discussion I've been having with Cisco on the matter is that they do
> not "see any demand" for LDPv6, and thus, won't develop it (on IOS XE).
> Meanwhile, it is actively developed, supported and maintained on IOS XR
> since 5.3.0, with new features being added to it as currently as 7.1.1.
> >>
> >> Needless to say, a bunch of other vendors have been supporting it for a
> while now - Juniper, Nokia/ALU, Huawei, even HP.
> >>
> >> IOS XR supporting LDPv6 notwithstanding, Cisco's argument is that "the
> world" is heavily focused on deploying SRv6 (Segment Routing). While I know
> of one or two questionable deployments, I'm not entirely sure much of the
> world is clamouring to deploy SR, based on all the polls we've done at
> various NOG meetings and within the general list-based operator community
> >>
> >> So I just wanted to hear from this operator community on whether you
> would be interested in having LDPv6 support to go alongside your LDPv4
> deployments, especially if you run native dual-stack backbones. Or if your
> focus is totally on SRv6. Or if you don't care either way :-). Thanks.
> >>
> >> Mark.
> >
> >
> >
> > --
> > Tim:>
>
>
>
> --
> ++ytti
>


--
Tim:>
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On 10/Jun/20 20:45, Saku Ytti wrote:

> I'm pretty sure that one or more of Mark, Gert or Tim are thinking
> SR/MPLS IPv6 when they say SRv6?

Oh, not at all, Saku.

> No one in their right minds thinks SRv6 is a good idea, terrible snake
> oil and waste of NRE. SR/MPLS IPv6 of course is terrific.
>
> LDPv6 and SRv6 seem like an odd couple, LDPv6 SR/MPLS IPv6 seem far
> more reasonable couple to choose from. I have my favorite.

I've been tracking SR since it began making "waves" in Paris at a
previous MPLS/SDN/IPv6 Congress meeting a a 2013, or thereabouts. Plenty
of promise about being a decent alternative to LDPv6 (which had been on
my mind since 2008).

In the end, as you rightly point out, it's been much ado about nothing.

To this day, I am yet to hear from a single operator about all the
chanting I hear from vendors - and not just SRv6, but SR in general. 7
years and counting.

Mark.
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On 10/Jun/20 21:17, Gert Doering wrote:

>
> We do have IOS XEs today (ASR920), and based on that, we're not going
> to buy new IOS XE devices any time soon.
>
> The amount of... strangeness... that this BU considers acceptable
> is... not.

It's been a week of trying to get them to see reason.

Tough for their "unified" case with the IOS XR team are delivering the
goods.

Mark.

On 10/Jun/20 21:20, Gert Doering wrote:

> Oh. Indeed, sorry for being unclear here.
>
> SR/MPLS sounds like a good idea (reducing label state).
>
> SR/IPv6 does not sound convincing.

+1.

2010 - 2019 has been a decade of "pushing stuff".

2020 is the year of deciding what snake oil no longer deserves energy,
the Coronavirus notwithstanding.

Mark.

On 10/Jun/20 21:36, Phil Bedard wrote:
> In its simplest form without TE paths, there isn't much to SRv6. You use a v6 address as an endpoint and a portion of the address to specify a specific VPN service. You completely eliminate the label distribution protocol.

A BGPv6-free core is a decent use-case for us.

Much simplicity has been enjoyed by removing that in the IPv4 world.

Mark.
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On Thu, 11 Jun 2020 at 00:48, Mark Tinka <mark.tinka@seacom.mu> wrote:

> On 10/Jun/20 21:36, Phil Bedard wrote:
> > In its simplest form without TE paths, there isn't much to SRv6. You use a v6 address as an endpoint and a portion of the address to specify a specific VPN service. You completely eliminate the label distribution protocol.
>
> A BGPv6-free core is a decent use-case for us.

100% Eliminating label forwarding in core is not an asset, it is a
liability. Label forwarding is fast, cheap and simple[0]. You can do
it with on-chip memory in constant time. IP lookups are slow,
expensive and complex[0]. SRv6 marketing is false, bordering dishonest
marketing of an unclean abomination of a protocol. Every HW designer
has sighed in relief when I've said I don't care about it, because
it's also very HW unfriendly, like IPv6 generally. Unfortunately SRv6
is somewhat easy to market with the whole 'it's simple, just IP'
spiel.

[0] None of this is hard to measure, it is a known fact. And all of it
matters, you can measure lower jitter for MPLS than IP, you can better
carry DDoS traffic when using MPLS compared to IP and you can have
more ports in front-plate for the same money, by spending external
memory SERDES for WAN ports.



--
++ytti
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On Wed, 10 Jun 2020 at 22:36, Phil Bedard <bedard.phil@gmail.com> wrote:

> In its simplest form without TE paths, there isn't much to SRv6. You use a v6 address as an endpoint and a portion of the address to specify a specific VPN service. You completely eliminate the label distribution protocol.

Then do IPv6-in-IPv6, and attach the inner IPv6 header to VRF,
pseudowire, what-have-you.

It is clear market needs tunnelling, and we should all understand that
colour of tunneling doesn't matter, what matters is how many bytes of
overhead does the tunnel add (the more bytes, the more bps leverage
attacker gets) and what is the cost of looking up the headers.
Evaluating 40B IPv6 and 4B MPLS tunneling headers based on objective
desirable qualities of tunneling, MPLS is blatantly better. But if
someone does not like MPLS, fair-game, they should have ability to do
IPV6 in IPv6 in IPv6 in IPv6, go crazy.

I'm not saying we can't improve over MPLS header, we can. But IPv6 is
just objectively inferior by key metrics of 'goodness' of tunneling.

--
++ytti
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On 11/Jun/20 06:51, Saku Ytti wrote:

> Every HW designer
> has sighed in relief when I've said I don't care about it, because
> it's also very HW unfriendly, like IPv6 generally. Unfortunately SRv6
> is somewhat easy to market with the whole 'it's simple, just IP'
> spiel.

Mine have sighed in disbelief that I don't share their vision of an
SR(v6) world :-).

What's funny is that the ASR920 does not support SRv6, which I think is
more due to hardware limitations than a lack of coding kiddies.
Conversely, you don't need new bits of hardware to support LDPv6.

Today, there is no box that supports LDPv4 that cannot support LDPv6, by
just extending the code. No further hardware needed.

Instead, I'm being asked to "upgrade" to the NCS540 so that I can get
LDPv6. You, sometimes, have to wonder in what world these folk live.

It's a Coronavirus era now - people want to hold on to all the $$ they
don't have, and only spend it where they will extract the most value.
Boeing and Airbus are struggling to reach customers that have pending
deliveries; now isn't the time for vendors to posture. We need value,
not product.

Mark.

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On Thu, 11 Jun 2020 at 10:37, Mark Tinka <mark.tinka@seacom.mu> wrote:

> Mine have sighed in disbelief that I don't share their vision of an
> SR(v6) world :-).

I don't like to conflate these two; SR is great, SRv6 is horrible
abomination. SR is what MPLS should have been day1, but it probably
was easier to market LDP than to say 'we need to change all IGP
protocols'.

--
++ytti
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On Wed, Jun 10, 2020, at 20:51, Mark Tinka wrote:

> Well, according to them, SRv6 is winning customers over, and nobody
> wants LDPv6. Then again, they have LDPv6 in IOS XR; figures.

Well, given their (Cisco's) braindead policy regarding non-implementation of LDPv6 on XE, no wonder people are looking for alternatives, and SRv6 is one of them. And don't forget SRv6 is also heavily associated (marketing-wise) with 5G....

Back to our friends and their policy: It happens that in certain regions of the world, if you want to be an ISP other than the "establishment" (== incumbent + "first alternatives" that started 20-25 years ago), you MUST have LNS (if you want to stay in business). If like many, you are kind of stuck with Cisco because it's Cisco, the only decent solution to have LNS is ASR1K (running XE). Also add ASR920 which has a number of uses. Also, in order to stay in business, you may want to offer L3VPN services, which brings you to doing MPLS. You say MPLS, you say LDP, and there you go, your backbone remains v4-based for the next eternity.

There also seems to be a lack of global vision. Tyry to ask your favourite vendor what do you need in order to be able to offer IPv4-L3VPN, IPv6-L3VPN and L2VPN (mainly point-to-point - NO MAC learning) over a backbone that does NOT use any single IPv4 address (backbone-side). Because you can do it on a backbone that does not use any single IPv*6* address, but you may want to go forwards, not backwards. Add a LNS in the mix (the v4 addresses for the LNS go in VRFs - that's not backbone). Add a money, rack space and power needed constraints in the mix. This exercise looks challenging with other vendors too, but with Cisco it's just impossible.

Of course, Cisco says there is no demand for one simple reason : the people talking with Cisco account managers (or whatever they are called) are only rarely those that care about technical stuff. They may want some features on the CPEs (like "ui uant SDWAN"), but for anything else (including backbone equipment) they only want lower prices. You end up with everybody having to deal with a specific platform in real life to dream about a specific feature, yet the vendor to consider that "nobody wants it".

--
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On 11/Jun/20 09:42, Saku Ytti wrote:

>
> I don't like to conflate these two; SR is great, SRv6 is horrible
> abomination. SR is what MPLS should have been day1, but it probably
> was easier to market LDP than to say 'we need to change all IGP
> protocols'.

Fair point.

Mark.
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> Mark Tinka
> Sent: Wednesday, June 10, 2020 6:19 PM
>
> Hi all.
>
> Just want to sample the room and find out if anyone here - especially
those
> running an LDP-based BGPv4-free core (or something close to it) - would be
> interested in LDPv6, in order to achieve the same for BGPv6?
>
> A discussion I've been having with Cisco on the matter is that they do not
> "see any demand" for LDPv6, and thus, won't develop it (on IOS XE).
> Meanwhile, it is actively developed, supported and maintained on IOS XR
> since 5.3.0, with new features being added to it as currently as 7.1.1.
>
> Needless to say, a bunch of other vendors have been supporting it for a
> while now - Juniper, Nokia/ALU, Huawei, even HP.
>
> IOS XR supporting LDPv6 notwithstanding, Cisco's argument is that "the
> world" is heavily focused on deploying SRv6 (Segment Routing). While I
know
> of one or two questionable deployments, I'm not entirely sure much of the
> world is clamouring to deploy SR, based on all the polls we've done at
various
> NOG meetings and within the general list-based operator community
>
> So I just wanted to hear from this operator community on whether you
> would be interested in having LDPv6 support to go alongside your LDPv4
> deployments, especially if you run native dual-stack backbones. Or if your
> focus is totally on SRv6. Or if you don't care either way :-). Thanks.
>
Hey Mark,
My stance is that should I go with anything "new" for label distribution the
MPLS SR/SPRING is getting to a point where it might be mature enough.
Also "BGP free core" means internet won't talk to your core -i.e. free to
use private addressing -so no need for v6 at all in the "underlay" (as
hipsters call it these days).
Alternatively using public "infrastructure subnet" (i.e. not advertised to
the Internet) for a "BGP free core", the aim is to make money of the core
-what additional revenue stream am I getting by enabling v6 in the
underlay/management plane that would offset the pain of dealing with the
increased bug surface?

And with regards to the XE/XR discrepancies, I mentioned my prophecy a
number of times, I think XE future in SP products portfolio is next to none.



adam

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Saku Ytti wrote on 11/06/2020 05:51:
> Unfortunately SRv6 is somewhat easy to market with the whole 'it's
> simple, just IP' spiel.
it's not "just IP": it's ipv6 with per-router push / pop operations on
ipv6 extension headers, i.e. high touch in areas which are known to be
deeply troublesome on hardware.

In this regard alone, the specification is problematic enough that it's
unearthed a bug in the IPv6 standard (rfc8200).

Nick
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On 11/Jun/20 10:32, adamv0025@netconsultings.com wrote:

> Hey Mark,
> My stance is that should I go with anything "new" for label distribution the
> MPLS SR/SPRING is getting to a point where it might be mature enough.

"Getting to a point" doesn't really work if you are actively running a
network today :-).

While I do agree that going with the new thing is always a good plan,
one has to truly consider the overall gain vs. labour required to get there.

Going from static routing to an IGP + BGP makes sense when you scale up.

Switching from Distribute Lists to Prefix Lists makes sense when you
scale up.

Route summarization after you dump your old Cisco 2501 for an ASR9901
doesn't add value any longer.

You get the idea.

The position about not needing a label distribution protocol in SR is
actually quite sexy. But considering how powerful router control planes
are nowadays, especially when they are being virtualized on or off
chassis, I just don't see the gains expected by removing LDP and going
SR, on a box and code that supports both. Yes, if you are talking about
dumping a spaghetti of RSVP tunnels, that makes sense as there is a gain
in day-to-day network administration. But in this case, we are just
speaking about LDP.

10 years ago, we worried about how well an IP network would scale
running OSPF or IS-IS. With control planes what they are today, who
really cares anymore? You may recall we've been running CSR1000v for
route reflection since 2014 - millions of routes being carried everyday,
converging in seconds. We've never had to think about those boxes until
last year when we did the server hardware refresh as a matter of course,
not because anything was struggling.

What I'm saying is not all new tech. NEEDS to get deployed just because
it's new. If that was the case, we'd all be running Inter-AS DSCP over
IPoDWDM :-).


> Also "BGP free core" means internet won't talk to your core -i.e. free to
> use private addressing -so no need for v6 at all in the "underlay" (as
> hipsters call it these days).

Careful with that one - Cisco's proposal to me was to run my IPv6
network on link-local :-). Don't encourage them, hehe.


> Alternatively using public "infrastructure subnet" (i.e. not advertised to
> the Internet) for a "BGP free core", the aim is to make money of the core
> -what additional revenue stream am I getting by enabling v6 in the
> underlay/management plane that would offset the pain of dealing with the
> increased bug surface?

I don't know about you, but my BGP-free core is inaccessible from the
world even if it lives in public-IPv4 land. That's how pure MPLS
forwarding works. You'd have be "inside" to reach it (IGP).

Also, if you link every feature to a revenue stream, you'll never deploy
RPKI or DNSSEC :-).


>
> And with regards to the XE/XR discrepancies, I mentioned my prophecy a
> number of times, I think XE future in SP products portfolio is next to none.

Which is fine - but customers are spending real money and need to keep
real networks running with real costs for real years. If Cisco want to
kick IOS XE to the side, let customers know so we can make informed
decisions about where to purchase gear.

The current state-of-the-art is that kit you buy today is probably good
years after standard depreciation policies, probably longer. If Cisco's
model is to throw boxes away sooner than that like they did in the old
days, that is not consistent with where the tech. has gotten to in the
past 2 decades.

Mark.
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On 11/Jun/20 09:58, Radu-Adrian FEURDEAN wrote:

> Well, given their (Cisco's) braindead policy regarding non-implementation of LDPv6 on XE, no wonder people are looking for alternatives, and SRv6 is one of them.

Which doesn't track because there are a number of IOS XE boxes that do
not support SRv6, and probably never will. Meanwhile, no issue with
those boxes supporting LDPv6, as they already support LDPv4.


> And don't forget SRv6 is also heavily associated (marketing-wise) with 5G....

Well, we all know the farce that is 5G.

Also, not all of us run mobile networks, and even for those that do,
there are probably a few that don't buy into the snake oil, especially
those that offer native IPv6 to their mobile customers :-).


> Back to our friends and their policy: It happens that in certain regions of the world, if you want to be an ISP other than the "establishment" (== incumbent + "first alternatives" that started 20-25 years ago), you MUST have LNS (if you want to stay in business). If like many, you are kind of stuck with Cisco because it's Cisco, the only decent solution to have LNS is ASR1K (running XE). Also add ASR920 which has a number of uses. Also, in order to stay in business, you may want to offer L3VPN services, which brings you to doing MPLS. You say MPLS, you say LDP, and there you go, your backbone remains v4-based for the next eternity.

Which I would understand if Cisco's strategy, as a company, was anti-LDP.

But when you have the IOS XR team actively supporting LDP and adding new
features with each major release, the split brain is obvious. You can't
come to me under a "unified" organizational banner, and then tell me you
are a-thousand companies internally. If you choose to fork code into
IOS, IOS XE, IOS XR, NX OS, or whatever new flavour of the decade, don't
make that my problem. Customers don't buy code; they buy boxes that are
built for the task. The code that comes with it is the code that comes
with it.

Moreover, IOS XE also has its own split BU's. So getting IOS XE fixed
for the ASR920 doesn't necessarily mean you get it fixed for the
ASR1000. I mean, how much more complicated does a business have to be?


>
> There also seems to be a lack of global vision. Tyry to ask your favourite vendor what do you need in order to be able to offer IPv4-L3VPN, IPv6-L3VPN and L2VPN (mainly point-to-point - NO MAC learning) over a backbone that does NOT use any single IPv4 address (backbone-side). Because you can do it on a backbone that does not use any single IPv*6* address, but you may want to go forwards, not backwards. Add a LNS in the mix (the v4 addresses for the LNS go in VRFs - that's not backbone). Add a money, rack space and power needed constraints in the mix. This exercise looks challenging with other vendors too, but with Cisco it's just impossible.

That's because it's not about l3vpn6 or l2vpn6; it's about IPv6. And you
can't business-case IPv6.

Some vendors fail to understand that IPv6 is not the money-maker. IPv6
is what attracts the customer to the network so that the money can flow.
It's a means to an end, not the end in itself.


>
> Of course, Cisco says there is no demand for one simple reason : the people talking with Cisco account managers (or whatever they are called) are only rarely those that care about technical stuff. They may want some features on the CPEs (like "ui uant SDWAN"), but for anything else (including backbone equipment) they only want lower prices. You end up with everybody having to deal with a specific platform in real life to dream about a specific feature, yet the vendor to consider that "nobody wants it".

One of the reasons I've never been keen on working for a vendor is
tunnel vision becomes easy. As an operator, you have a much wider view
of what's happening in the real world. When a vendor decides to home-in
on EoMPLS and VPLS being better signaled by LDP vs. BGP, you end up with
situations where they track user-demand through the number of TAC cases
the feature caused. The fewer the TAC cases, the lower the demand. Very
scientific.

Nobody is going to demand LDPv6 because the over-arching problem is a
lack of IPv6 deployment at global scale. If folk don't deploy IPv6, they
will not think about LDPv6, RSVPv6, e.t.c. But to make it worse, if the
vendors keep encouraging the "big-spending" mobile operators to maintain
IPv4 by selling CGN licenses, it's kind of back-to-front, isn't it? No
operator unwilling to deploy IPv6 but favours CGN is ever going to ask a
vendor about LDPv6, especially if the vendor is in charge of building
and operating that backbone as a "professional, managed service".

Ultimately, we are not asking for an ASIC re-spin. We are not asking for
a doubling of forwarding capacity. We are not asking for a greener
chassis. We are not asking for 100Gbps ports. All of which are
physically impossible. We are asking for LDP to extended to support
IPv6. Really, how hard is that?

Mark.


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>
> I don't like to conflate these two; SR is great, SRv6 is horrible
> abomination. SR is what MPLS should have been day1, but it probably
> was easier to market LDP than to say 'we need to change all IGP
> protocols'.
>

Nope that was not the main reason.

Main reason was the belief that labels MUST be locally significant - and
not domain wide unique. Just look at Juniper's SRm6 or now SRH ... they
keep this notion of locally significant SIDs. It is deep in their DNA ...
still.

We argued about it a lot in cisco back in TDP days - and we lost.

- - -

Now to your runt that MPLS is great because of exact match perhaps you
missed it but number of solutions on the table (including RbR[**] I
recently proposed) use exact match 4B locator based lookup in the v6
packets to get from segment end to segment end.

On the other hand your comments about greatness of MPLS ... simplified data
plane and depending on the hardware difference in jitter (in sub ms ranges
- if that even matters) comes up with a lot of control plane complexity
when you want to build a network across all continents, yet keep it scoped
from IGP to areas or levels. No summarization in MPLS in FECs is something
we should not sweep under the carpet.

Best,
R.

[**] -
https://mailarchive.ietf.org/arch/msg/ipv6/Ef05LFFij45mm8fM8hLFXknxoIA/
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Mark Tinka wrote on 11/06/2020 10:48:
> We are asking for LDP to extended to support IPv6. Really, how hard
> is that?
Nearly impossible, apparently.

It would require a change of mindset.

Nick
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