Thus spake "Tony Finch" <dot(_at_)dotat(_dot_)at>
On Tue, 28 Aug 2007, Thomas Narten wrote:
As a data point, ARIN (in the last year) adopted a IPv6 PI for
end sites doing multihoming policy. Such end sites get a /48.
FWIW, technically the PI policy also covers folks that are single-homed,
though the bar is higher for them to get a block. It's not expected that
many single-homed sites will bother getting one, though; if so, and it
becomes an operational problem, we'll raise the bar even higher.
I thought that routes in the IPv6 DFZ were not supposed to be more
specific than /32.
Back when the IETF was trying to stuff the operational world into TLAs and
NLAs, completely ignoring the need of folks to multihome or do BGP-based TE
(i.e. intentional deaggregation), that was the supposition.
The reality is that routes longer than that (I've seen /128s, for that
matter) are accepted, up to /48 in general practice. ARIN compromised at
/48 for PI because (a) that's what a "site" is supposed to get according to
the IETF, and (b) it makes it easy to filter them all out if they ever
become a problem for the DFZ. The IETF conveniently told vendors that they
should not wire specific prefix lengths into hardware, so this hasn't
resulted in any problems like we saw when CIDR was introduced.
S
Stephen Sprunk "God does not play dice." --Albert Einstein
CCIE #3723 "God is an inveterate gambler, and He throws the
K5SSS dice at every possible opportunity." --Stephen Hawking
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