In message <e22a56b3-68f1-4a75-a091-e416800c4...@delong.com>, Owen DeLong write s: > >>> > >> Which is part one of the three things that have to happen to make ULA > >> really bad for the internet. > >> > >> Part 2 will be when the first provider accepts a large sum of money to > >> route it within their public network between multiple sites owned by > >> the same customer. > >> > > > > That same customer is also going to have enough global address > > space to be able to reach other global destinations, at least enough > > space for all nodes that are permitted to access the Internet, if not > > more. Proper global address space ensures that if a global destination > > is reachable, then there is a high probability of successfully reaching > > it. The scope of external ULA reachability, regardless of how much > > money is thrown at the problem, isn't going to be as good as proper > > global addresses. > > > _IF_ they implement as intended and as documented. As you've > noted there's a lot of confusion and a lot of people not reading the > documents, latching onto ULA and deciding ti's good. > > It's not a big leap for some company to do a huge ULA deployment > saying "this will never connect to the intarweb thingy" and 5-10 years > later not want to redeploy all their addressing, so, they start throwing > money at getting providers to do what they shouldn't instead of > readdressing their networks.
IPv4 think. You don't re-address you add a new address to every node. IPv6 is designed for multiple addresses. > > For private site interconnect, I'd think it more likely that the > > provider would isolate the customers traffic and ULA address space via > > something like a VPN service e.g. MPLS, IPsec. > > > One would hope, but, I bet laziness and misunderstanding trumps > reason and adherence to RFCs over the long term. Since ULA > won't get hard-coded into routers as unroutable (it can't), Actually it can be. You just need a easy switch to turn it off. The router can even work itself out many times. Configure multiple interfaces from the same ULA /48 and you pass traffic for the /48 between those interfaces. You also pass routes for that /48 via those interfaces. > when > people do bad stuff with it, it will work and since it works, they won't > go read the documentation explaining that what works is a bad > idea. > > >> Part 3 will be when that same provider (or some other provider in the > >> same boat) takes the next step and starts trading routes of ULA space > >> with other provider(s). > >> > >> At that point, ULA = GUA without policy = very bad thing (tm). > >> > >> Since feature creep of this form is kind of a given in internet history, > >> I have no reason to believe it won't happen eventually with ULA. > >> > > > > So I'm not sure I can see much benefit would be of paying a > > huge amount of money to have ULA address space put in only a > > limited part/domain of the global route table. The only way to > > have ULA = GUA is to pay everybody on the Internet to carry it, and > > that is assuming that everybody would be willing to accept the money > > in the first place. That'd be far more expensive than just using GUA > > addresses for global reachability. > > > > No... The way it will work is that use of ULA as pseudo-GUA will > spread slowly like cancer through the network. > > When provider A and provider B both have customers throwing lots > of money at them to route their ULA, provider A and provider B will > swallow hard and agree to exchange those routes in both directions. > > I wish I had your confidence in people doing the right thing, but, > there are enough examples of RFC-1918 space in the GRT that > I simply can't share your belief that it won't happen with ULA > which doesn't have the reliability problems that RFC-1918 had. > > Owen > > -- Mark Andrews, ISC 1 Seymour St., Dundas Valley, NSW 2117, Australia PHONE: +61 2 9871 4742 INTERNET: ma...@isc.org
