In message <3qnxhn426dzj...@spike.porcupine.org>
Wietse Venema writes:
>
> Curtis Villamizar:
> > Are you saying they only looked at the primary NS record? Maybe I
> > misread a prior post but I thought you meant primary MX record. The
> > former, if true, would be even more broken.
>
> There are no primary/secondary NS records; what matters are the NS
> records for his domain the parent zone name server hands out.
>
> Wietse
Wietse,
You are correct if you want to be pedantic, but ...
The NS RR are typically delivered in a fixed order, the order in the
zone file, and while perhaps neither NS RR is properly a primary in
the sense that MX has preference, lots of code uses the first NS
first, then tries the second.
For example, the bind documentation (Section 6.3 "Zone File") says:
The set of resource information associated with a particular name
is composed of separate RRs. The order of RRs in a set is not
significant and need not be preserved by name servers, resolvers,
or other parts of the DNS. However, sorting of multiple RRs is
permitted for optimization purposes, for example, to specify that
a particular nearby server be tried first.
So I think that might count as at least weak evidence of current
practice, but that has been my experience. My primary NS is better
connected (at a colocation site, near an IX, with GbE the slowest hop)
and is listed first and the secondary doesn't get much use from
outside (which is good since its connected via a MSO "business
Internet service" which is usable, but nothing like the colo).
Curtis
