Darden, Patrick S. wrote:
Was looking over 1918 again, and for the record I have only run into one network that follows:
"If two (or more) organizations follow the address allocation specified in this document and then later wish to establish IP connectivity with each other, then there is a risk that address uniqueness would be violated. To minimize the risk it is strongly recommended that an organization using private IP addresses choose *randomly* from the reserved pool of private addresses, when allocating sub-blocks for its internal allocation."
I added the asterisks.
You're supposed to choose ula-v6 /48 prefixs randomly as well... Any bets on whether that routinely happens? While you're home can probably randomly allocate subnets out of a /8 or /12 for a while without collisions, nobody that's actually building a subnetting plan for a large private network is going to be able to get away with that in v4.
--Patrick Darden
-----Original Message----- From: Darden, Patrick S. Sent: Wednesday, August 06, 2008 9:19 AM To: 'Leo Bicknell'; nanog@nanog.org Subject: RE: Is it time to abandon bogon prefix filters?
Yes. 1918 (10/8, 172.16/12, 192.168/16), D, E, reflective (outgoing mirroring), and as always individual discretion.
--Patrick Darden
-----Original Message----- From: Leo Bicknell [mailto:bicknell@ufp.org] Sent: Wednesday, August 06, 2008 9:10 AM To: nanog@nanog.org Subject: Is it time to abandon bogon prefix filters?
"Bogon" filters made a lot of sense when most of the Internet was bogons. Back when 5% of the IP space was allocated blocking the other 95% was an extremely useful endevour. However, by the same logic as we get to 80-90% used, blocking the 20-10% unused is reaching diminishing returns; and at the same time the rate in which new blocks are allocated continues to increase causing more and more frequent updates.
Have bogon filters outlived their use? Is it time to recommend people go to a simpler bogon filter (e.g. no 1918, Class D, Class E) that doesn't need to be updated as frequently?