nanog mailing list archives

Re: IPv6 Address Planning


From: kawamura seiichi <kawamucho () mesh ad jp>
Date: Wed, 10 Aug 2005 09:18:37 +0900


hi

this is a very interesting topic

On 9-aug-2005, at 19:24, Cody Lerum wrote:

Here is our current plan, but we are looking for suggestions from  
people
who have been down this road before. The plan is to break out a /48  
for
our organization. Then break out the first /64 for loopbacks, and the
next /64 for point-to-point connections. The PTP /64 then breaks out
further into 1 /80 for core links, and 1 /80 for each of our
distribution sites. Within these /80's are individual /112's for PTP
links. What this will allow us to do is aggregate each sites PTP
connections into /80's within our IGP.

Hm, I would keep the first /48 apart for your own services. Addresses  
in that first /64 are nice and short.

agree. i would keep the first "several" /48s though, in case
your network grows.


what we do is we don't use anything greater than a /64.
(excluding loopbacks)
main reason is because it becomes too much of a hassle 
to keep track of any prefixs greater than that.
the first few /48 blocks are reserved for own services and networks
and data centers. within these /48s we divide them into /56s
and define what they mean

example:
 2001:db8:a::/48 data center "a"
   2001:db8:a::/56 routers, ptp links etc
   2001:db8:a:0100::/56 ntp's dns's, etc.
   2001:db8:a:0200::/56 hosted streaming servers
   2001:db8:a:0300::/56 hosted web servers
   and so on

we did this because its easier to notice problems this way.
when an alarm is detected on our NMS at 2001:db8:a:0200::/56
we know right away that there is a problem at the streaming zone.
our main business is being an ISP for consumers, so
this might differ if you mainly serve corporate customers.

If you use /64s for router links, you can use eui-64 addressing  
within those, which has the advantage that you don't have to keep  
track of which router has the ...1 and which router has the ...2  
address. If you use a lot of vlans in your own network (as opposed to  
customer links) you may also want to endcode the vlan id in bits 48 -  
63. Makes everything really simple to debug!

i think this is the most important thing in
deploying IPv6 networks. make it simple to debug, and
that will make life a whole lot easier.

---
seiichi


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