On 10/21/08 4:56 PM, Brian E Carpenter allegedly wrote: > On 2008-10-22 07:01, Scott Brim wrote: >> The question is really about mapping. I wasn't in the room at that time >> (that I remember) but I think DNS was a lot more fragile than it is now, >> and more fragile than ALT. Personally I think we're okay as long as we >> can deploy the robustness the system is designed for. If Jon's problem >> was having IP forwarding depend on something fragile -- like >> the-then-DNS -- then I don't think there's a problem. If he objected in >> principle to depending on anything other than hop-by-hop routing then I >> guess he would still have a problem ... but then again he never liked >> route filtering either. > > There's no doubt Jon felt strongly about this. I'm not sure whether he > or Lixia was the originator of the following words in RFC 1958: > > 3.11 Circular dependencies must be avoided. > > For example, routing must not depend on look-ups in the Domain > Name System (DNS), since the updating of DNS servers depends on > successful routing. > > It might have been Lixia, because the point was explicit in her report > of the plenary discussion at IETF 33: > > " In addition to the need > for autoconfiguration on tools at low levels, renumbering requires > changes to high-level protocols. It also puts further reliance on the > DNS system to keep up-to-date address binding. To avoid circular > dependency, DNS servers themselves will require special treatment, > such as provider-independent addresses, assured connectivity, issues > that are yet to be explored. " > > Brian
Good morning, Brian. So the fundamental concern was about circular dependencies. In map-n-encap there are two different pieces routing information distribution mechanisms, to reach locators and to reach EIDs. We just need to be sure that sources for mapping information (to reach EIDs) are reachable in the global scope. _______________________________________________ rrg mailing list [email protected] https://www.irtf.org/mailman/listinfo/rrg
