nanog mailing list archives
Re: IPv6 end user addressing
From: Owen DeLong <owen () delong com>
Date: Sat, 6 Aug 2011 09:48:55 -0700
On Aug 6, 2011, at 3:40 AM, Mukom Akong Tamon wrote:
On Fri, Aug 5, 2011 at 11:18 PM, Doug Barton <dougb () dougbarton us> wrote:For example, if you reserve a /48 per customer but actually use the first /56 out of it, you are safe if _you_ need the other /56 for some reason, or if the customer needs to expand into the full /48.+1. Be generous in planning and then assign what makes operational sense. Be sure to make sure that as you dole out smaller than blocks to customers that requested from your RIR, you preserve your ability to give a client a second block from the same aggregatable range.
The way to address this better is to use allocation by bisection to your customers rather than giving them /56s. If you give a site a /48, it is very unlikely they will ever need an additional prefix for that site. Of course if you're talking about a customer that is using a single connection to you to feed multiple sites, that's a different issue and will require additional planning. For anyone that already understands allocation by bisection, you can skip the rest of this message. What I mean by allocation by bisection is simply issuing prefixes such that each issued prefix has the largest possible contiguous aligned space available for expansion. Let's assume 2001:db8::/32 as our starting point and that we are assigning /48s to 50 end sites from it. (I'm skipping the whole hierarchy to fit inside a /32 and keep the example simple). We'd assign 2001:db8::/48 for our own infrastructure and support machines. The first customer would get 2001:db8:8000::/48. The next customer would get 2001:db8:4000::/48, then 2001:db8:c000::/48. In the next round, we'd assign 2001:db8:2000::/48, 2001:db8:6000::/48, 2001:db8:a000::/48 and 2001:db8:e000::/48 This would be followed by …1000::/48, …3000::/48, …5000::/48, …7000::/48, …9000::/48, …b000::/48, …d000::/48, and …f000::/48. At this point, we've assigned 15 customers, and each of them could be expanded from /48 to /36 without invading any of our existing assignments. Continuing, we would assign the next 16 customers as: 2001:db8:0800::/48, 2001:db8:1800::/48, 2001:db8:2800::/48, 2001:db8:3800::/48, 2001:db8:4800::/48, 2001:db8:5800::/48, 2001:db8:6800::/48, 2001:db8:7800::/48, 2001:db8:8800::/48, 2001:db8:9800::/48, 2001:db8:a800::/48, 2001:db8:b800::/48, 2001:db8:c800::/48, 2001:db8:d800::/48, 2001:dbu:e800::/48, 2001:db8:f800::/48 That brings us to 31 customers all of whom have room to expand their /48 up to a /37 (though I wouldn't recommend doing /37s as they are not nibble-aligned, so, outside of exceptional circumstances, you would be unlikely to expand in place beyond /40 at this point.) The next 32 customers would fill in the 2001:db8:?400::/48 ranges and the 2001:db8:?c00::/48 ranges. This limits those customers now to /38s. Owen
Attachment:
smime.p7s
Description:
Current thread:
- Re: IPv6 end user addressing, (continued)
- Re: IPv6 end user addressing Tim Franklin (Aug 09)
- Re: IPv6 end user addressing Ryan Malayter (Aug 09)
- Re: IPv6 end user addressing William Herrin (Aug 09)
- Re: IPv6 end user addressing David Conrad (Aug 09)
- Re: IPv6 end user addressing Joel Jaeggli (Aug 09)
- Re: IPv6 end user addressing Owen DeLong (Aug 06)
- Re: IPv6 end user addressing Cameron Byrne (Aug 06)
- Re: IPv6 end user addressing Joel Jaeggli (Aug 06)
- Re: IPv6 end user addressing Doug Barton (Aug 05)
- Re: IPv6 end user addressing Mukom Akong Tamon (Aug 06)
- Re: IPv6 end user addressing Owen DeLong (Aug 06)
- Re: IPv6 end user addressing Mukom Akong Tamon (Aug 06)
- Re: IPv6 end user addressing William Herrin (Aug 06)
- Re: IPv6 end user addressing Jimmy Hess (Aug 06)
- Re: IPv6 end user addressing Owen DeLong (Aug 06)
- Re: IPv6 end user addressing Jimmy Hess (Aug 06)
- Re: IPv6 end user addressing Matthew Moyle-Croft (Aug 09)
- Re: IPv6 end user addressing Mohacsi Janos (Aug 09)
- Re: IPv6 end user addressing Owen DeLong (Aug 09)
- Re: IPv6 end user addressing Valdis . Kletnieks (Aug 09)
- Re: IPv6 end user addressing Owen DeLong (Aug 09)
- Re: IPv6 end user addressing Mark Andrews (Aug 09)
- Re: IPv6 end user addressing Mohacsi Janos (Aug 09)