RE: No, SMTP is IPv4, Was: SMTP and IPv6

[Vasilenko Eduard <vasilenko.eduard=40huawei.com@xxxxxxxxxxxxxx>]

• So I don't believe that IPv4 will always be with us, in any sense.  

Not in the next 20 years. With all current problems still kept in IPv6 (DHCP blocked, multi-homing does not work, enormous complexity on the 1^st hop).

The current “consensus” is such that IPv6 would not move on the Enterprise side. Only Telco, only Telco, they have the address shortage and the abovementioned technological problems are not their problems.

Ed/

From: Keith Moore <moore@xxxxxxxxxxxxxxxxxxxx>
Sent: Monday, July 1, 2024 18:06
To: Phillip Hallam-Baker <phill@xxxxxxxxxxxxxxx>
Cc: ietf@xxxxxxxx
Subject: Re: No, SMTP is IPv4, Was: SMTP and IPv6

 

On 7/1/24 10:32, Phillip Hallam-Baker wrote:

 

The fundamental problem here is that if I am running any sort of large mail service, I am evaluated on deliverability by my customers, not by the protocols I use. If 5% of email servers are IPv4 only, I have to support them or my deliverability will fail and I will get complaints. IPv4 addresses are not a scarce commodity as far as operators of mail services goes and so IPv4 will always be with us as far as SMTP is concerned.

Remember BITNET?   I remember people insisting that BITNET would never disappear, people who were arguing that BITNET was still growing (if slowly) every month... right up until it disappeared almost overnight.

Because once everyone on BITNET had IP service, people realized it wasn't worth maintaining BITNET in addition to maintaining their IP networks.   This was true even though BITNET offered some services that didn't have direct IP equivalents.   (I believe many of those BITNET sites were actually transmitting that traffic over IP by then, so they had already saved the cost of the leased phone lines that they had once used.   It wasn't the communications cost so much as the administrative overhead that led to BITNET's demise.)

So I don't believe that IPv4 will always be with us, in any sense.   Once IPv6 access is ubiquitous, people will start asking why they need to continue administering IPv4, except perhaps to communicate locally with legacy devices.

I'm actually in favor of explicitly deprecating the public IPv4 Internet, setting the date well in advance at which carriers start filtering IPv4 BGP advertisements and stop forwarding IPv4 traffic except by explicit arrangement.   I nominate Jan 1, 2033.   We need to stop insisting that sites must continue to administer two IP networks forever.

Keith