"Programmers can't get IPv6 thus that is why they do not have IPv6 in their applications"....

Wed Nov 28 03:18:59 UTC 2012

I think that we are missing a significant part of this conversation. 

Even if programmers never write a line of code that invokes IPv6, they need
to accommodate the effects of all the other programmers who aren't writing a
line of IPv6 code. CGN renders most application logs useless unless they
record source port as well as address. For many industries, logging of
transactions in a manner that allows you to track back to the originator of
the transaction is not optional. And yes that does translate to track back
to the ISP who (when presented with the appropriate piece of paper) can
convert the timestamp /IP address/ port combination to the customer who is
responsible for the account.

Even if programmers never write a line of code that invokes IPv6, they had
better be testing their Internet facing applications against users in pure
IPv4 environments; users in pure IPv6 environment using each of  the
transition mechanism, and users in dual-stack environments.

I've spent more than a small amount of time explaining to vendors that
AI_ADDRCONFIG is a really good hint flag to have set. One vendor responded
that the change would require retesting everything. I'm afraid that he
wasn't happy when I pointed out that they obviously hadn't tested the first
time and that as the customer, I was entitled to at least one full set of
(successful)  pre-delivery testing.

--Dave

> -----Original Message-----
> From: Owen DeLong [mailto:owen at delong.com]
> Sent: Tuesday, November 27, 2012 6:48 PM
> To: Jared Mauch
> Cc: nanog at nanog.org
> Subject: Re: "Programmers can't get IPv6 thus that is why they do not have
> IPv6 in their applications"....
> 
> >
> >> I agree that some of it comes down to knowledge; most programmers
> >> learn from experience and lets face it unless you go looking your
> >> unlikely to run into IPv6 even as of yet. I believe as the ISP
> >> implements IPv6 and companies get more demand on the customer facing
> >> side of things it will pick up quickly.
> >
> > Sure, using gethostbyname() is certainly easier to find code examples,
but
> not impossible to find other examples.
> >
> 
> http://owend.corp.he.net/ipv6
> 
> Pretty much everything you need to know about taking your applications
> from mono-stack to dual-stack.
> 
> Includes an example application implemented in IPv4 only and ported to
dual
> stack in C, PERL, and Python.
> 
> >> In our datacenters all our software is built with IPv6 addressing
> >> supported but we have yet to build the logic stack as we are waiting
> >> for the demand. It makes no sense to build all the support just
> >> because when there are other important things to do.
> >
> > There is something else.  Many people "cheated" and stuck a 2^32 number
> in an integer datatype for their SQL or other servers.  They don't work as
well
> with 2^128 sized IPs.  They have to undertake the actual effort of storing
> their data in a proper datatype instead of cheating.  I've seen this
over-and-
> over and likely is a significant impediment just as the gethostbyname vs
> getaddrinfo() system call translations may be.
> >
> 
> It's actually pretty easy to change the datatype in an SQL database, so
that
> shouldn't be that much of an impediment.
> 
> Owen
> 