[107019] in North American Network Operators' Group
Re: It's Ars Tech's turn to bang the IPv4 exhaustion drum
daemon@ATHENA.MIT.EDU (Iljitsch van Beijnum)
Wed Aug 20 04:47:46 2008
From: Iljitsch van Beijnum <iljitsch@muada.com>
To: Kevin Loch <kloch@kl.net>
In-Reply-To: <48AB2D18.3070203@kl.net>
Date: Wed, 20 Aug 2008 10:47:39 +0200
Cc: nanog list <nanog@nanog.org>
Errors-To: nanog-bounces@nanog.org
On 19 aug 2008, at 22:29, Kevin Loch wrote:
> I thought there was an issue with duplicate address detection with /
> 127
> (RFC3627)?
Don't know about that, but the all-zeroes address is supposed to be
the all-routers anycast address. Cisco doesn't implement this, so /127
works on those, but there are some other vendors that do, so /127
won't work on those boxes. (And wouldn't it be funny if Cisco decided
to start implementing the all-routers anycast address...)
> /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.
I like using EUI-64 addressing, i.e.:
!
interface vlan666
ipv6 address 2002:dead:beaf:666::/64 eui-64
!
This has the advantage that you don't have to explicitly assign an
address to each router, it all works out automatically and you can
copy/paste configs from one box to the other.
I also like to put the VLAN ID in bits 48 - 63. This makes the IPv6
addressing plan REALLY simple...
