Re: draft-ietf-dnsop-hardie-shared-root-server-06.txt

[Randy Bush <randy@psg.com>]

> This wording was in response to comments by Bernard Aboba about the
> design of anycast in IPv6, and obviously came before the IPv6 anycast
> analysis draft came out.  According to Bernard's comments, the current
> specs disallow this use.  I've cc'ed him on this so he can comment on
> any further discussion.  Pending further comment, I will plan to
> incorporate the change.

many people are working on un-breaking v6 anycast

>>   One potential problem with using shared unicast addresses is that
>>   routers forwarding traffic to them may have more than one available
>>   route, and those routes may, in fact, reach different instances of
>>   the shared unicast address.  Some applications, whose communication
>>   consists of independent request-response messages each fitting in a
>>   single UDP packet presents no problem.  Other applications, in which
                              /
>>   multiple packets must reach the same endpoint (e.g., TCP) may fail
>>   or present unworkable performance characteristics in some
>>   circumstances.  Split-destination failures may occur when a router
>>   does per-packet (or round-robin) load sharing, a topology  change
                                                   ^ and/or when
>>   occurs that changes the relative metrics of two paths to the same
>>   anycast destination, etc.