Will a single /27 get fully routed these days?

Owen DeLong owen at delong.com
Sun Jan 26 04:36:33 UTC 2014

On Jan 25, 2014, at 13:59 , Sander Steffann <sander at steffann.nl> wrote:

> Hi,
>> Yeah, its been a while since I had to get involved in this.  We have a
>> customer with their own IPv4 allocation that wants us to announce a /27 for
>> them. Back in "the day", it was /24 or larger or all bets were off.  Is
>> that still the case now?
> This is still the case today.
> I wonder what will change (if anything) when ARIN runs out of IPv4 space. Geoff's current predictions say Feb 2015, but I wouldn't be surprised if it turns out to be sooner than that. But, when that happens ARIN will only have the 'Dedicated IPv4 block to facilitate IPv6 Deployment' [1] left, and it will use 'a minimum size allocation of /28 and a maximum size allocation of /24' for that block. The block is meant for things like dual stacked DNS servers, NAT64 and other IPv6 deployments where a bit of IPv4 is still necessary.
> I wonder how reachable those systems will be... Will people adjust their filters, or will most usage of this block (and thereby all new entrants in the ISP market in the ARIN region) just be doomed?

That's actually may not be the best question. That block will come from within a specific prefix and I suspect that ISPs and the like will adjust their filters FOR THAT PREFIX.

Consider the possibility of a policy change which allows the transfer of smaller blocks (current ARIN policy limits this to /24 minimum, but ARIN policy is not immutable, we have a policy development process so that anyone who wants to can start the process of changing it.)


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