4 ms·

What are the implications of this for things like DNS caching, replication, root servers, negative lookup, etc? If you run your own DNS and want to create gigab

What are the implications of this for things like DNS caching, replication, root servers, negative lookup, etc? If you run your own DNS and want to create gigabytes of NUM records, that's great. But I wouldn't expect Cloudflare, Google, etc. to want to cache that data, so that could create a situation where most of your DNS is cached somewhere, so it's distributed, fast, reliable, and local, but your NUM records aren't cached, so now you've got servers that are out of sync, or are falsely returning negative results, or you have to implement a mechanism that treats NUM records differently in clients. I don't know if any of these concerns are applicable, but I'm curious.

eat_veggies 6y ago
If recursive resolvers like Cloudflare, Google, or your ISP stopped caching _num.* records, the servers wouldn't go out of sync or falsely return negative results, since DNS caching and updates are more of a "pull" model than "push" with consensus (so it's just like your computer's L1, L2, L3, memory, and disk caches, but with eviction based on TTL). So _num records would end up forwarding all the way to the authoritative DNS server for the zone you're trying to access. You'd just have a slower experience than with your normal DNS queries, but you wouldn't observe anything weird.
elliottinvent 6y ago
I think it's only caching that is a factor here. It's certainly possible that DNS resolvers could refuse to cache, or somehow restrict caching (e.g. ignore TTLs) for: 1. any record from a _num. zone (independent records 2. any record from *.num.net (hosted records) 3. any TXT record starting "@n=X" (all NUM records) 4. any TXT record over X bytes Since DNS is becoming more and more consolidated with DoH and DoT, one decision from a player like Google or Cloudflare could have a big impact here. I think it depends how the records are being used, if one domain has gigabytes of NUM records then I think resolvers are more likely to act against that domain in particular rather the protocol as a whole. If gigabytes of NUM records were stored in cache from millions of different domains, then I'd hope that DNS resolvers would see the benefit of caching these records for users. If Cloudflare cached NUM records and Google didn't, then Cloudflare would be quicker for many operations (e.g. dialling a domain, fetching useful data with Siri / Alexa, etc).

eat_veggies 6y ago

If recursive resolvers like Cloudflare, Google, or your ISP stopped caching _num.* records, the servers wouldn't go out of sync or falsely return negative results, since DNS caching and updates are more of a "pull" model than "push" with consensus (so it's just like your computer's L1, L2, L3, memory, and disk caches, but with eviction based on TTL). So _num records would end up forwarding all the way to the authoritative DNS server for the zone you're trying to access. You'd just have a slower experience than with your normal DNS queries, but you wouldn't observe anything weird.

elliottinvent 6y ago

I think it's only caching that is a factor here. It's certainly possible that DNS resolvers could refuse to cache, or somehow restrict caching (e.g. ignore TTLs) for: 1. any record from a _num. zone (independent records 2. any record from *.num.net (hosted records) 3. any TXT record starting "@n=X" (all NUM records) 4. any TXT record over X bytes Since DNS is becoming more and more consolidated with DoH and DoT, one decision from a player like Google or Cloudflare could have a big impact here. I think it depends how the records are being used, if one domain has gigabytes of NUM records then I think resolvers are more likely to act against that domain in particular rather the protocol as a whole. If gigabytes of NUM records were stored in cache from millions of different domains, then I'd hope that DNS resolvers would see the benefit of caching these records for users. If Cloudflare cached NUM records and Google didn't, then Cloudflare would be quicker for many operations (e.g. dialling a domain, fetching useful data with Siri / Alexa, etc).