Creating an IPv6 addressing plan for end users

Liudvikas Bukys Liudy at
Wed Mar 23 10:56:38 CDT 2011

Hi, I saw your document "Preparing an IPv6 Addressing Plan" after its URL
was posted to NANOG.

I have one small comment that perhaps you would consider in future

The use of decimal numbers coded in hexadecimal is introduced in section
3.2, "Direct Link Between IPv4 and IPv6 Addresses", without discussion.
 It's also implicit in section 4.9 when encoding decimal VLAN numbers in
hexadecimal address ranges.

My opinion is that this may be a source of confusion, and should be
explicitly described somewhere before section 3.2, as a deliberate
implementation choice that makes it easier for human operators to configure
and recognize deliberately-chosen mappings between decimals in IPv4
addresses and integers and corresponding fields in hexadecimal address

Without an explicit discussion, this point may be missed by some readers --
especially since this is a training document.

Just my opinion!

I'm also curious as to whether this describes the way the world has already
settled on, or whether this is a novel, controversial, or
only-occasonally-observed technique.  I see that RFC 5963 - IPv6 Deployment
in Internet Exchange Points (IXPs) of August 2010 does mention BCD encoding
of both ASNs and IPV4 digits, so I guess it's not that novel.

> > -----Original Message-----
> > From: Nathalie Trenaman [mailto:nathalie at]
> > Sent: Wednesday, March 16, 2011 5:05 AM
> > To: nanog at
> > Subject: Creating an IPv6 addressing plan for end users
> >
> > Hi all,
> >
> > In our IPv6 courses, we often get the question: I give my customers a
> > /48 (or a /56 or a /52) but they have no idea how to distribute that
> > space in their network.
> > In December Sander Steffann and Surfnet wrote a manual explaining
> > exactly that, in clear language with nice graphics. A very useful
> > document but it was in Dutch, so RIPE NCC decided to translate that
> > document to English.
> >
> > Yesterday, we have published that document on our website and we hope
> > this document is able to take away some of the fear that end users seem
> > to have for these huge blocks.
> > You can find this document here:
> >
> > (PDF)
> >
> > I look forward to your feedback, tips and comments.
> >
> > With kind regards,
> >
> > Nathalie Trenaman
> > RIPE NCC Trainer
> >
> >

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