In message <AANLkTimsB6Uj-jpogLg08Q-RZDUB-+C9c5KMzcKTQKmQ@mail.gmail.com>, Chri stopher Morrow writes:
On Sun, Oct 31, 2010 at 2:01 PM, George Bonser <gbonser@seven.com> wrote:
ula really never should an option... except for a short lived lab, nothing permanent.
I have a few candidate networks for it. =A0Mostly networks used for clustering or database access where they are just a flat LAN with no "gateway". =A0No layer 3 gets routed off that subnet and the only things talking on it are directly attached to it.
why not just use link-local then?
If you had actually every tried to use link-local then you would know why you don't use link-local.
eventually you'll have to connect that network with another one, chances of overlap (if the systems support real revenue) are likely too high to want to pay the renumbering costs, so even link-local isn't a 100% win :( globally-unique is really the best option all around.
2^40 is 1099511627776. The chances of collision are so low that one really shouldn't worry about it. You are millions of times more likely of dieing from a asteroid 1-in-500,000[1]. If you merge thousands of ULA and don't consolidate then you start to have a reasonable chance of collision. Even if you do have colliding ULA prefixes you don't necessarially have colliding subnets when merging companies. Just allocate subnet randomly. It's not like 2^16 internal subnets is going to be a major routing problem. Mark [1] http://www.livescience.com/environment/050106_odds_of_dying.html -- Mark Andrews, ISC 1 Seymour St., Dundas Valley, NSW 2117, Australia PHONE: +61 2 9871 4742 INTERNET: marka@isc.org