3 ms·
> but now that I learned that SERVFAIL is not cached on [...] intermediate DNS servers [0] I thought so too, but at least some do cache according to Cloudflare
by yourad_io 5y ago
> but now that I learned that SERVFAIL is not cached on [...] intermediate DNS servers [0]
I thought so too, but at least some do cache according to Cloudflare's blog post:
> Consequently, 1.1.1.1, 8.8.8.8, and other major public DNS resolvers started issuing (and caching) SERVFAIL responses.
https://blog.cloudflare.com/october-2021-facebook-outage/ https://blog.cloudflare.com/october-2021-facebook-outage/
- im3w1l 5y agoFacebook is so large that even caching the SERVFAIL with a TTL measured in seconds should cut down a lot of traffic.
- daper 5y agoAs I understand my favorite resolver - unbound - has separate "infra" cache that also caches RTT times, and "down" status of name servers: https://nlnetlabs.nl/documentation/unbound/unbound.conf/#infra-keep-probing https://nlnetlabs.nl/documentation/unbound/unbound.conf/#inf...