[dns-operations] "best practices" for restaring internal DNS servers

[Mark Andrews]

In message <7699449B-57AB-499C-93C2-DCF4049E42E9 at nic.br>, Rubens Kuhl writes:
> 
> It depends. I can tell from experience that for a large outbound SMTP syste=
> m(1M+ accounts), loss of DNS cache can hit it pretty hard. =

Except we are not talking about the loss of a cache (recursive
nameserver) which requires failover to a different cache.

We are talking about the difference to starting with a empty cache
or a pre-populated cache and whether there is a significant difference
from the clients perspective and for how many seconds there is a
difference.  There is definitely some additional latency for the
first few queries but after how many queries do you fall within the
normal latency profile?

-- 
Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: marka at isc.org