5 ms·

The root zone has grown considerably thanks to a number of new gTLDs, but currently sits at around 2 MB: https://www.iana.org/domains/root/files https://www.ia

The root zone has grown considerably thanks to a number of new gTLDs, but currently sits at around 2 MB: https://www.iana.org/domains/root/files https://www.iana.org/domains/root/files That's in human-readable ASCII. A wire format could probably shave a chunck off that, but distributing deltas instead of re-downloading the whole file each time a change is made would further reduce the required data transfer amounts to mere bytes per day on average.

NKosmatos 6y ago
Thanks for your reply, I was thinking about the actual files containing the DNS entries and not the root file which contains all of the DNS servers. As I understand it the root file is needed in case you want to bootstrap your own DNS server so as to be able to find all the other authoritative servers. What about the actual DNS database files?
- vesinisa 6y ago
  You are talking about the root seed list (the NS records for the root label .) - essentially the anycast IPv4/6 addresses for the 13 root servers. This file is provided in the first section of the linked page. The second file on the page contains the actual current root zone, which is a 2 MB file containing all the delegation entries for TLDs (like com., org. and de.) immediately below the DNS root (.). This is what the article is talking about caching locally at your ISP's recursive name server. The whole global DNS can never be downloaded or even built as a local database due to its distributed nature, and also for technical reasons. Below the root zone at TLD level (like com.) there is no way to enumerate all the individual registrations (like google.com., ycombinator.com., microsoft.com. etc) You always query for a specific individual name + record pair, instead of being allowed to download the entire zone. So even if you somehow would be able to contact every authoritative DNS server on Internet at some point in time, there is no standard query to ask them to give you all their records, making building a full local copy of the global DNS database impossible.

NKosmatos 6y ago

Thanks for your reply, I was thinking about the actual files containing the DNS entries and not the root file which contains all of the DNS servers. As I understand it the root file is needed in case you want to bootstrap your own DNS server so as to be able to find all the other authoritative servers. What about the actual DNS database files?

vesinisa 6y ago
You are talking about the root seed list (the NS records for the root label .) - essentially the anycast IPv4/6 addresses for the 13 root servers. This file is provided in the first section of the linked page. The second file on the page contains the actual current root zone, which is a 2 MB file containing all the delegation entries for TLDs (like com., org. and de.) immediately below the DNS root (.). This is what the article is talking about caching locally at your ISP's recursive name server. The whole global DNS can never be downloaded or even built as a local database due to its distributed nature, and also for technical reasons. Below the root zone at TLD level (like com.) there is no way to enumerate all the individual registrations (like google.com., ycombinator.com., microsoft.com. etc) You always query for a specific individual name + record pair, instead of being allowed to download the entire zone. So even if you somehow would be able to contact every authoritative DNS server on Internet at some point in time, there is no standard query to ask them to give you all their records, making building a full local copy of the global DNS database impossible.