Reverse for a /23

[Fred Viles]

gah at ugcs.caltech.edu (glen herrmannsfeldt) wrote in 
<83rnac$qum at gap.cco.caltech.edu>:

>Stephen Amadei <amadei at dandy.net> writes:
>
>(snip about RFC2317)
>
>>O.K... I had heard RFC2317 was for doing reverse breaking _any_ of the
>>octets... not just the last one.
>
>>Then what would be done, for say a /17 reverse?  Create 32768 reverse
>>files?
>
>No, 128 files with 256 entries each.
>
>For a /9 you would need 32768 files, though with that many hosts
>you might delegate some of them.

No, I think you are making the same mental error.  /9 is no different 
from /17, in that all you *need* is 128 delegations from the higher
level zone.  So a /9 takes 128 files with 64K entries each.

I think that's why RFC2317 is applicable only for /25 or smaller.  
Anything larger doesn't need the "trick" because it is handled
perfectly well with standard delegation.

- Fred