George Bonser wrote:
We have decided to initiate the process of becoming IPv6 capable. We have requested and received a block of addresses which, after reading some of the discussion here, I fear may be too small to suit our needs (a /48). To better understand how to proceed and in an attempt to get it right (or close to right) the first time, I am soliciting opinions and comments from other network operators.
Given you topology your direct assignment request should properly reflect the number of sites you expect to need to need to serve. At a /48 per site it starts to look rational.
It appears from earlier discussions on this list that while many networks will not filter a /48 announcement in their routing tables, others will. We have data centers and offices in three regions of the globe; North America, Europe, and Asia/Pacific. We are also multihomed as well as having some direct peering. I can break my /48 into /56 nets for each facility. My thought process here being that if I have the same transit providers at all sites, I can announce the /48 from my primary location and that would get announced by the transit provider. They would also accept my more specific routes but not announce them outside of their AS. So traffic originating outside of my transit provider would flow toward them following the /48 and they then move the traffic to the final destination based on the more specific and in the case the traffic has no more specific route, hand the traffic to my main location for me to sort out or just black hole it. There are two problems with this approach. 1: We are unreachable from anyone filtering a /48 and 2: I could see a situation where traffic crosses the Pacific, is handed to my transit provider, and then crosses the Pacific again to get to the destination resulting in poor performance.
So it now seems to me that maybe a larger block might be the best answer but being an "end user" the policies seem pretty restrictive on getting a /32 though I might qualify for several /48 blocks (at least one in each registry region). So how does one reconcile having a diverse, multihomed organization on several continents while at the same time trying to do the right thing, not requesting more resources than we need, and trying to be friendly to the various networks' operations by advertizing only what we need to? Is it unreasonable to get separate /48 blocks for operations in Europe, North America, and Asia or possibly two for Asia (one in China and one for Asia outside of China)? While that still won't help us with connectivity from networks filtering /48's, it might relieve much of the back and forth transit across oceans to get traffic originating from and destined for the same continent to stay there. I don't have a problem with regional backhaul tying an office /56 to a data center announcing a /48 and using that data center as a communications hub for the region. It also assumes a transit provider I am paying to haul my traffic will take "more specifics" for internal use even if they aren't advertizing them.
I am just trying to minimize the stupidity and barriers to scale on my side of the equation.