On Mar 27, 2012 7:09 PM, "Brian E Carpenter" <[email protected]> wrote: > > Dave, > > On 2012-03-28 09:28, Dave Taht wrote: > > On Thu, Mar 22, 2012 at 3:50 PM, Brian E Carpenter < > > [email protected]> wrote: > > > >> On 2012-03-22 12:33, homenet issue tracker wrote: > >>> #4: Use of ULAs > >>> > >>> CN1 in the -02 text says ULAs should be provisioned by default. Do we > >>> agree? > >> Yes, by the CER (MUST). > >> > >> It's much less clear for all other routers on site. I would prefer that > >> no other router provisions a ULA prefix if the CER has already delegated > >> one. > >> > > > > Since it is nearly impossible to learn a subnet prefix that is unused > > unless all devices share a routing protocol, I have generally preferred to > > generate unique ULAs per routing device. > > Our two statements are not inconsistent... obviously, if a router comes > up and does not hear about a ULA prefix from another router, it may be > appropriate to generate a new one. But if we have a prefix delegation > mechanism in place, that may be sufficient. > > > > > > >>> And if so, should they be preferred over globals? > >> Yes. > >> > >> > > This part I don't quite understand. I would prefer global prefixes to > > always take precedence over ULAs. > > I'd like ULAs to try to talk only to ULAs. ULAs should not escape into the > > global DNS, but should end up in local dns. > > ULAs should really only be used to talk to ULAs, so when I say 'prefer ULAs', > I mean prefer a pair of ULAs to a pair of globals. In case it isn't clear, > in my mind the problem is always address *pair* selection. So that means > that a host should do something like this in the default case: > > Do I have a ULA? > If yes, does the other guy have a ULA (in the same prefix)? > If yes, use the two ULAs. > Else, use two globals. > > I'm hoping 3484bis will result in this. >
In the general case, you don't believe ula and global should have communication at all? Or just a matter of source selection when multiple address types are available to a given host ? Cb > > > > Even with 'happy eyeballs', having a means to disable a ULA -> global > > connection by default saves 100s of ms in the bad cases. > > Agreed. > > Brian > > > > >>> The new > >>> 3484-bis has changed so they are not *unless* a specific /48 for the > >> site > >>> is added to the 3484 policy table with higher precedence than globals. > >> We > >>> should design something that works when disconnected from the Internet. > >> We'll have to deal with whatever 3484bis ends up saying. If it does > >> require an explicit policy table entry table, that will require > >> a mechanism, associated with the prefix delegation mechanism. > >> > > > > OK, I will re-read, thx for the update.. > > > > > >>> Also, we currently say nothing about ULA-only devices and their > >>> reachability from outside the homenet; do we want to? > >> I don't see what there is to say; they aren't reachable, and that's > >> a feature. > >> > >> Brian > >> _______________________________________________ > >> homenet mailing list > >> [email protected] > >> https://www.ietf.org/mailman/listinfo/homenet > >> > > > > > > > _______________________________________________ > homenet mailing list > [email protected] > https://www.ietf.org/mailman/listinfo/homenet
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