Search RPD Archives
Limit search to: Subject & Body Subject Author
Sort by:

[AfriNIC-rpd] Anycast prefix's

Andrew Alston aa at
Fri May 11 11:08:36 UTC 2007

Hi All,


Before I actually type up and submit a policy proposal, I wanted some
opinions on the adoption of a policy regarding the allocation of /24
prefix's for the purpose of anycast.


This could be done in two ways, either through a modification of the
current v4 allocation policy or through the addition of an overriding
policy, I think the former makes more sense however.


Very basic concept:


Because you cannot announce anything smaller than a /24 into the global
tables, in order to provide for anycast you need to announce an entire
/24, and in an anycast situation this is announced from multiple asn's.
AfriNIC's current v4 policy states that the minimum allocation size on
initial is a /22.  To use a /22 for anycast when you potentially are
only using 3 addresses in the block is a huge waste.


Also, with anycast prefix's it is potentially possible to have multiple
anycast blocks that are using only 2 or 3 addresses in the prefix (see
ASN 112 prefix that uses 3 address in the /24).  This
means that a company that utilizes general allocation /24 space for the
purposes of anycast could be in trouble when applying for more space due
to lack of space usage.


To my knowledge RIPE also has a policy that allows for this kind of


If people think this is viable, I'll type up a proposed policy or a
proposed modification and send it through, just trying to get a sense of
what the feeling is.  If anyone wants more details on anycast before
commenting on the policy, feel free to drop me an email as well.




Andrew Alston 

TENET - Chief Technology Officer

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <>

More information about the RPD mailing list