On Thu, Oct 7, 2021 at 8:28 AM Masataka Ohta <mohta@necom830.hpcl.titech.ac.jp> wrote:
My comment on the rfc is that it is simply wrong.
See also:
https://datatracker.ietf.org/doc/html/rfc3258 While it would be possible to have some process withdraw the route for a specific server instance when it is not available, there is considerable operational complexity involved in ensuring that this occurs reliably. Given the existing DNS failover methods, the marginal improvement in performance will not be sufficient to justify the additional complexity for most uses.
which was our consensus at that time in DNSOP. I have no idea why it was forgotten.
It wasn't forgotten. Folks gained a lot of experience with anycast DNS between 2002 and 2006. Not withdrawing the routes when the servers are deemed malfunctioning turned out not to be an operationally sound practice. The theory offered in 3258 was wrong. Regards, Bill Herrin -- William Herrin bill@herrin.us https://bill.herrin.us/