Fwd: Re: RPSL support for 32 bit ASN

Larry,

>     There was considerable discussion during the development of the
>RPSLng spec (RFC4012) concerning modifying the syntax for existing attributes.
>The consensus was that this approach should not be taken and that
>new attributes should be created wherever an IPv6 address could
>appear so as not to break existing tools.
>draft-uijterwaal-rpsl-4bytesas-ext-00.txt
>appears to have abandoned this approach.

That is correct.  I looked at the problem and creating new attributes for
ASN32 would cause the number of attributes to expand as N^2.  In other
words, for each kind of attribute, there would be a version for IPv4-ASN16,
IPv6-ASN16, IPv4-ASN32 and IPv6-ASN32.  If something else is changed in
the future, this will result in 8 versions of essentially the same
attribute.  This does not look very attractive to me.

Also, contrary to IPv4 and IPv6, we are very likely to have a mixed
ASN16 and ASN32 world "forever".  In fact, the ASN32 standard is
specifically designed with this in mind, and the two worlds can
live happily together.

So, any tool will have to be upgraded sooner or later, the only question
is when and how.

In both cases (change existing attributes or create new ones), people will
have to upgrade when they move into the ASN32 world.   The difference is
in the code change.  In my draft, the tools will have to recognize 2
versions for an AS.  Changing attributes means that tools will have to
check if the ASN16 or ASN32 version is there,  then parse that to get
the information.   In the end, this doesn't look like a big difference
to me.

Henk


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Henk Uijterwaal                           Email: henk.uijterwaal(at)ripe.net
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