/25's prefixes announced into global routing table?

Sat Jun 22 11:57:45 UTC 2013

On Sat, Jun 22, 2013 at 12:44 AM, Owen DeLong <owen at delong.com> wrote:
>>>      The forwarding hardware is generally going to be the limit, and
>>> that's going to be painful enough as we approach a half million
>>> prefixes.
>>
>> True. And that's why we must avoid IPv6.
>
> This is not only wrong, it makes no sense whatsoever.

Neither did the first part of his statement. Gigabit srams are neither
particularly cheap nor particularly better suited to implementing a
FIB than plain old dram.

On Sat, Jun 22, 2013 at 1:19 AM, Brandon Martin
<lists.nanog at monmotha.net> wrote:
> So here's a question: has anyone done any musings/reasearch on how big of a
> global IPv6 table we could expect given current policies if IPv6 were as
> widely deployed and used as IPv4 (or if IPv4 didn't exist)?

Too soon to tell.

On the one hand, we shouldn't have the registry-driven fragmentation.
They're trying hard to allocate enough addresses for all foreseeable
demand, not just near term, and they're leaving space to bump the
netmask for the next request when it comes. They're also selecting
policies which discourage multihomed end users from breaking up their
ISP's block instead of getting their own. On the other side of the
hump with IPv4 in decline, both of these should reduce the total
number of announcements chosen by each organization.

On the other hand, IPv6 addresses consume upwards of 4 times the bits
in the FIB.

On the fence, the tools for traffic engineering have not changed, the
registries are making no attempt to allocate in a manner that
facilitates TE filtering, and there's still no better way than a BGP
announcement for an end-user to multihome. Number transfers for
mergers, acquisitions and divestitures, and renumbering in general
suffer from all the same ailments they do in IPv4.  At 128 bits
instead of 32 bits, all of these factors should impact IPv6 the in
same manner they have impacted IPv4.

Regards,
Bill Herrin

-- 
William D. Herrin ................ herrin at dirtside.com  bill at herrin.us
3005 Crane Dr. ...................... Web: <http://bill.herrin.us/>
Falls Church, VA 22042-3004