Re: Recommended DNS server for a medium 20-30k users isp

[William Herrin via NANOG <nanog () lists nanog org>]

On Fri, Aug 8, 2025 at 2:17 AM Måns Nilsson via NANOG
<nanog () lists nanog org> wrote:
> anycast unbound, preferably on something more mature than Linux, so like
> FreeBSD or OpenBSD.

You don't need anycast DNS for 30k users. Stay away from anycast
unless you really, really, really know what you're doing.

DNS is also TCP and no commodity DNS software environment implements
an anycast TCP stack, only the normal unicast stack. Route splitting
shows up in the most unexpected places and it won't just give you a
bad day, it'll give you a bad month with intractable and seemingly
(but not really) intermittent problems that are challenging to nail
down.

Regards,
Bill Herrin


-- 
William Herrin
bill () herrin us
https://bill.herrin.us/
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