When ARIN prepared for the IPv4-pocolypse[1], they put aside a /10 for
**smaller than /24 allocations**. Our default ruleset will not allow
those, even though they will be for various pieces of critical dual-stack
infrastructure to help IPv6-only systems survive.
RIPE is currently[2] announcing smaller blocks to test how wide spread
acceptance of these blocks are. The results are not so good, but better
than last time :).
I just committed an example configuration line to the sample OpenBGPd
filter set:
allow from any inet prefix 23.128.0.0/10 prefixlen 24 - 28
You may need to adjust your filter set to accept these addresses. With
this rule, I now see the test announcements over my AMS-IX link.
According to the RIR Comparative Policy Overview 2015-02[3], no other RIR
has such a policy, so you don't need to add other filters to cover other
regions.
[1] https://www.arin.net/announcements/2014/20140130.html
[2]
https://labs.ripe.net/Members/emileaben/has-the-routability-of-longer-than-24-prefixes-changed
[3]
https://www.nro.net/rir-comparative-policy-overview/rir-comparative-policy-overview-2015-02#2-6
--
Pardon this fortune. Database under reconstruction.
