Why are there only 13 root name servers?

Answered Wed, 2 Jan 2002

> I'm very wondering why there are only 13 root servers on globally.
> Some documents explain that one of the reason is technical limit on Domain
> Name System (without any detailed explanation).
> From my understanding, it seems that some limitation of NS record numbers
> in DNS packet that specified by certain RFCs, or just Internet policy stuff.
>
> Which one is proper reason?

It's a technical limitation. UDP-based DNS messages can be up to 512 bytes
long, and only 13 NS records and their corresponding A records will fit into a DNS message that size.

> P.S.: I've read your dns&bind 3rd and 4th Ed. very impressively. Thanks! :)

You're welcome!

cricket