If I have two upstream providers as an SMB, how do you propose I handle 
failover between the two of them without PAT?

> On Jun 19, 2026, at 1:57 PM, Gary Sparkes <[email protected]> wrote:
> 
> Zero need for PAT. NPT means you *don't* have to PAT. Deploying PAT would be 
> EXTRA steps.
> 
> NPT means you're already 1:1 automatically, and you just open firewall ports 
> for anything you need to inbound external access. No additional configuration 
> or setup needed.
> 
> PAT immediately eliminates most of the SMB benefits. The only one you retain 
> is the V4 allocation cost reduction .... maybe.
> 
> Any business internet will be giving you at least something like a /60 or 
> /56, so as long as you subnet within that size space there's zero reason to 
> put in additional effort for PAT and all the downsides it brings along with 
> it.
> 
> -----Original Message-----
> From: [email protected] <[email protected]>
> Sent: Friday, June 19, 2026 1:48 PM
> To: [email protected]
> Cc: Marco Moock <[email protected]>; Gary Sparkes <[email protected]>; 
> [email protected]
> Subject: Re: IPv4 flag day
> 
> The SMB use case is absolutely PAT. They aren’t going to 1:1 NAT all of their 
> internal hosts to both providers provided IPv6 space.
> 
>> On Jun 19, 2026, at 1:16 PM, Gary Sparkes via NANOG <[email protected]> 
>> wrote:
>> 
>> The cybercafe? Faster and more reliable online gaming. Better VOIP services 
>> for communication.
>> 
>> Gaming is something that *HUGELY* benefits from IPv6/NAT elimination.
>> 
>> The SMB? More reliable/consistent SIP experience for their phones.
>> Cheaper network hardware for the same throughput. Reduced complexity.
>> Reduced costs (address space) if they're exposing anything externally
>> / need external inbound access. (All wins I've gained for my
>> customers, and yes, they're all either dual stack or v6 with edge
>> translation for some networks, but with reduced expenses overall and
>> more reliable/performant networks)
>> 
>> Realistically, the only NAT that v6 should ever need is NPTv6 for the 
>> multihoming scenario (IEEE should just capitulate on that one, it just makes 
>> sense and it's not PAT that gives us all our problems in the first place), 
>> the rest just don't make sense and re-introduce complexity and issues that 
>> should be eliminated.
>> 
>> IPv6 enabled me to rip out a LOT of NAT workaround code from systems I 
>> support, which greatly simplified a lot of things. Re-introducing PAT into 
>> V6 land as a common practice would, once again, require re-adding all those 
>> insane hacks and workarounds and decreasing reliability.
>> 
>> We shouldn't need to solve those issues when we can eliminate them entirely.
>> 
>> -----Original Message-----
>> From: Pedro Prado via NANOG <[email protected]>
>> Sent: Friday, June 19, 2026 1:01 PM
>> To: North American Network Operators Group <[email protected]>
>> Cc: Marco Moock <[email protected]>; Pedro Prado <[email protected]>
>> Subject: Re: IPv4 flag day
>> 
>> … which sounds right (not implementing something you don’t need).
>> 
>> “Need” has a different interpretation for those inside a simple network and 
>> those interconnecting that network to everything else - a separation of 
>> values that Nat and even pat happens to handle pretty well IMHO, for the 
>> most part anyway, bar the well known issues.
>> 
>> What value the granularity of addresses inside a SMB brings to the outside 
>> if the connectivity works without that? What does global-capable 128-bit 
>> addressing help a cyber cafe?
>> 
>> I would hope that the research that goes into solving NAT/PAT issues
>> would trickle into improvements to the end to end upper protocols
>> which would eventually be unaware of how the network operates, similar
>> to how L2 is transparent today (bar MTU mismatches…)
>> 
>> *Pedro Martins Prado*
>> [email protected] / +353 83 036 1875 (FaceTime & WhatsApp)
>> 
>>> On Fri 19 Jun 2026 at 15:33, Marco Moock via NANOG
>>> <[email protected]>
>>> wrote:
>>> 
>>>>> Am 19.06.26 um 08:35 schrieb Arie Vayner:
>>>>> To move IPv6 to the next level of SMB/enterprise adoption we need to
>>>>> make it easier to consume by the average SMB - which means stop
>>>>> saying "NAT is evil" or "NAT is not supported in IPv6", and unblock 
>>>>> relevant IETF work.
>>> 
>>> There are devices for SMB that support stateful IPv6 NAT if they
>>> really need this. Although, my experience is that most of the network
>>> infrastructure in SMB environments is created one time and never
>>> touched unless necessary. They will also not implement IPv6 with NAT
>>> unless they really need it. Same applies to various other protocols.
>>> 
>>> --
>>> Gruß
>>> Marco
>>> 
>>> Junk-Mail bitte an [email protected]
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