[dns-operations] Anycast vs. unicast NS

[Stephane Bortzmeyer]

On Fri, Mar 18, 2011 at 11:29:57AM -0400,
 David Miller <dmiller at tiggee.com> wrote 
 a message of 44 lines which said:

> Do you also recommend that your customers run *nix DNS servers and
> M$ DNS servers (you will want Win 4.0, 2000, 2008 servers in the mix
> - for diversity)?  Do you recommend BIND 8 in addition to several
> different versions of BIND 9 for customer implementations?  How
> about distribution, kernel, nic driver version?  The matrix of
> diversity that gives you "protection against any issue" approaches
> an infinite number of different configurations.

As with any engineering decision, there is a trade-off. Diversity is
good because it shields you against a problem in one implementation
and it is bad because it means you have to spend more money, human
resources, etc, to handle it. So, everyone decides to draw a line at
some point. I think that having only BIND 9 for a TLD is a very bad
idea. Still, .FR has only BIND 9 and NSD name servers, we don't try to
add PowerDNS, ANS, Atlas and djbdns in the NS RRset :-)