Why 13 DNS root servers?

Sun, 10 Nov 2013 20:11:00 +0000

Updated. Thanks to Carsten Strotmann, who chimmed in. The maximum packet is 576 octects as specified in RFC 791. Removing the headers, leaves ~512 octets for the payload. See https://ripe67.ripe.net/presentations/112-2013-10-16-dns-protocol.pdf. Numbers slightly updated.

So why are there (only) 13 root-nameservers? See the updates below, this scheme came into use in the 90ies.

A priming query is a query that a nameserver performs when it starts up to get a list of the root nameserver IP addresses. This is done to validate (and possibly update) the built-in list of the addresses it has. In the early days of the DNS, the maximum packet size was set to 512 bytes, so this list needed to fit in 512 bytes.

Root on Miek Gieben

Why 13 DNS root servers?