Re: RE: [Ext] Artificial Juniper SRX limitations preventing IPv6 deployment (and sales)

[Samaneh Tajalizadehkhoob via NANOG <nanog () lists nanog org>]

I am not checking my emails until Nov 14th, 2025. Thanks, Samaneh

On Nov 7, 2025, at 8:05 AM, Vasilenko Eduard via NANOG <nanog () lists nanog org> wrote:

In-line comments.

-----Original Message-----
From: Brandon Martin via NANOG <nanog () lists nanog org>
Sent: Thursday, November 6, 2025 18:43
To: North American Network Operators Group <nanog () lists nanog org>
Cc: Brandon Martin <lists.nanog () monmotha net>
Subject: Re: Artificial Juniper SRX limitations preventing IPv6 deployment (and sales)

On 11/6/25 01:33, Vasilenko Eduard wrote:
Hi Marting, All your messages are true. But these are not all the complexities.
Read here (if you 
like)https://urldefense.com/v3/__https://datatracker.ietf.org/doc/html/draft-fbnvv-v6ops-site-multihoming-03__;!!PtGJab4!7le9y8xarIneuMGuqxJqFLY6hNZzChrIy08_GwC_wtBC_fGyhimUStUQvrmhEMXvyhHN5CGmjo5SBsuSG6QDYEXTIh8$
 [datatracker[.]ietf[.]org].
to see how deep is the rabbit hole and why it is better not to touch it.

While I have not read that entire draft, I'm familiar with most of the challenges it espouses, and they are indeed 
issues to deal with.

However, what you seem to be missing is that, IF you are willing to deal with what is essentially the status quo in 
IPv4 when not doing true multi-homing using BGP or similar (broken end-to-end connectivity and/or address translation 
that changes without notification to hosts behind the border router), you can do the SAME THING in IPv6.
[EV:] Not at all.
One very big company has blocked DHCP on all mobiles (inside chipset). Hence, it is not possible to delegate IPv6 
prefix behind mobile link. Hence, E2E IPv6 story is broken.
At the same time, IETF doing everything possible to block NAT in any form. NAT is the primary method for SMB/SOHO in 
IPv4.
Another one big company (or the same?) has blocked DHCP on the major mobile OS. You have to use IPX-style SLAAC.
And so on.
IPv6 is very aggressive in the attempt to "change the world".
Telco people has found a work-around for this: they have put subscriber inside the tunnel and disabled all complexities 
because it is P2P.

We try not to because IPv6 lets us do things in potentially BETTER ways, specifically in ways that attempt to preserve 
end-to-end connectivity and notify hosts about addressing changes, but that's up to you as a network administrator.
[EV:] You see - it is what I am talking about. Small group of people know how would be "BETTER".
IMHO: this group already isolated themselves.

Indeed, that draft mentions both ULA+NPT66 and ULA+NAT66 as options and discusses the upsides and downsides of them 
noting that they basically mimic the present-day situation with IPv4 including the known downsides.
[EV:] The draft would be never published because it mentions all options, but IETF consensus is "to be silent about any 
form of NAT and cancel it from all documents".
It one of the 3 major factors that push me to believe that IPv6 would not be accepted by businesses.
Actually, IPv6 IETF people are effectively blocking themselves.

Only if you want to dynamically change the addressing that hosts see on their interfaces do you run into issues that 
are unique to IPv6 (unless you're one of the presumably vanishingly few people doing that with public IPv4 addresses 
from multiple carriers).  There are upsides to making that work, but you don't have to, and you, as network 
administrator, get to choose what you do.
[EV:] For the IPv6 mandatory E2E story, you have to have dynamic IP addresses, because you have to renumber your 
network automatically after the uplink is lost, because the prefix was delegated from the Telco. IPv6 addresses are 
ephemeral for small businesses and many branches of big businesses.

In fact, the only mechanisms that paper mentions that AREN'T essentially identical to the status quo with IPv4 are the 
PA-based mechanism using adjustable RA timers on the LAN and NPT44, and both of these are only because either you can't 
do it at all with IPv4 (the former) or because there's no interest (the former again, plus NPT44 is a thing just not 
commonly used in this application due to address-space runout).
[EV:] Of cause not identical. IPv6 is much more complex - it has much more options and a few order of magnitudes more 
challenges.

There are also approaches commonly referred to collectively as "SD-WAN"
that aren't discussed in that draft that are ALSO used with IPv4 and that are directly applicable to IPv6.  The most 
obvious one is to tunnel all your traffic to a (hopefully) nearby endpoint with true (BGP-based) multi-homed 
connectivity and use some hidden mechanism to choose which local connection (for which BGP-based multi-homing is 
presumably not
viable) sees the tunneled traffic.
[EV:] They are discussed - It is section 5.3 (more general). Yet, the specific corner case "SD-WAN" was not mentioned - 
it is a point for improvement, people may search specifically for it.

There's multiple ways to approach a problem, and the one I'm generally least fond of is "proclaim the problem 
intractable", but I guess the "your network, your choice" philosophy applies there, too.
[EV:] I predict that business people would choose to stay on IPv4.

The number of approaches available on IPv6 to solve this problem is indeed higher than at least the practical number of 
approaches available on IPv4 due to the more flexible nature of IPv6, but the solutions themselves don't necessarily 
have higher complexity.

--
Brandon Martin
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