On Oct 23, 2009, at 5:08 AM, Perry Lorier wrote:
WRT "Anycast DNS"; Perhaps a special-case of ULA, FD00::53?
You want to allow for more than one for obvious fault isolation
and load balancing reasons. The draft suggested using
<prefix>:FFFF::1 I personally would suggest getting a well known
ULA-C allocation assigned to IANA, then use <prefix>::<protocol
assignment>:1 <prefix>::<protocol assignment>:2 and
<prefix>::<protocol assignment>:3, where <protocol assignment>
could be "0035" for DNS, and "007b" for NTP, and if you're feeling
adventurous you could use "0019" for outgoing SMTP relay.
I thought ULA-C was dead... Did someone resurrect this unfortunate
bad idea?
I'm not sure, I've not checked for a pulse recently. Last I looked
it seemed that there was ULA-L and ULA-C, and most people were
saying use ULA-L unless you needed ULA-C, ULA-C seemed like a good
fit for this, if it's been buried then sure ULA-L would fit the bill
just as well.
Easily identified, not globally routable, can be pre-programmed
in implementations/applications ... ?
Exactly, seems easy, straight forward, robust, reliable and allows
for things like fate sharing and fail over.
Why pull this out of ULA? Why not pull it out of 0000/16 or one of
the other reserved prefixes?
With my proposal above it only requires a /96, seems silly to use up
an entire /16 on a /96 worth of bits. It shouldn't come out of
2000::/3 because that's globally routable and this is defined to sit
within locally scoped addressing.
No... You missed my point...
I was suggesting that 0000::/16 already had some assignments for stuff
somewhat like this,
so, why not use more of that prefix to get a /96 for this...
e.g. ::/0 == default, ::1/128 == Loopback, etc.
Why not use 0000:ffff::/64 to assign these addresses as:
0000:ffff::<inst:ance>:<serv:ice>
That is a 32 bit instance number and 32 bit port number, using up just
a /64.
I was not suggesting the entire /16 for this, the entire /16 there
isn't available.
I have no major thoughts either way as to exactly where the range
comes from other than it should be an easy to spot, and easy to type
range which suggests plenty of 0's :)
I figured 0000 was a good candidate since it's already partially in
use for
reserved special addresses.
Owen
