One of our customers was recently allocated a /20 netblock from ARIN.
I had just been ass-u-ming it was a /19 until I cross-checked our
announcement update with the request from the customer. Is this a
change in policy (I thought they only allocated /19 or bigger) or did
I miss something? If the former, are NSPs like Sprint planning to
update filters to route these new smaller blocks?
Mark
One of our customers was recently allocated a /20 netblock from ARIN.
I had just been ass-u-ming it was a /19 until I cross-checked our
announcement update with the request from the customer. Is this a
change in policy (I thought they only allocated /19 or bigger) or did
I miss something? If the former, are NSPs like Sprint planning to
update filters to route these new smaller blocks?
Check the ARIN page, http://www.arin.net/initial-isp.html.
Essentially, ARIN allocates a /21 or /20 of a "Reserved" /19. When our
downstream got a /19 from ARIN, he announced the full /19 to defeat the
Draconian Sprint 112 filters and copy-cats.
Check with your downstream. They probably have a reserved /19 they can
announce.
And, of course, double-check with ARIN as this isn't my customer we're
talking about. 
Mark D. Nagel <nagel@intelenet.net>, CCIE #3177
TTFN,
patrick
ARIN has made a slight change to make it easier for small ISPs to get
provider independant netblocks. They will assign a /20 and reserve the
adjacent /20, the customer is allowed to announce the entire /19.
For further information, please view http://www.arin.net/initial-isp.html
Jeremiah
Jeremiah Kristal
Senior Network Engineer
ICon CMT Corporation
jeremiah@iconnet.net
201-319-5764
x284 internal