[107009] in North American Network Operators' Group
Re: It's Ars Tech's turn to bang the IPv4 exhaustion drum
daemon@ATHENA.MIT.EDU (Kevin Loch)
Tue Aug 19 16:29:27 2008
Date: Tue, 19 Aug 2008 16:29:12 -0400
From: Kevin Loch <kloch@kl.net>
To: nanog list <nanog@nanog.org>
In-Reply-To: <48AB07D6.3030203@psg.com>
Errors-To: nanog-bounces@nanog.org
Randy Bush wrote:
>> In practice, many routers require the packet to go twice in the hardware if
>> the prefix length is > 64 bits, so even though it is a total waste of space,
>> it is not stupid to use /64 for point-to-point links and even for loopbacks!
>
> some of us remember when we thought similarly for /24s for p2p links,
> especially when using rip.
>
> and consider matsuzaki-san's dos vulnerability on a /64 p2p link. the
> prudent operational advice today is to use a /127.
I thought there was an issue with duplicate address detection with /127
(RFC3627)? /126 should work and lots of folks use /112 which is a more
human-friendly bit boundary. /112 is also good for multiple access
vlans and just about anything that isn't using autoconfig.
- Kevin
