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Re: backup DNS question




On Jul 26, 2004, at 10:47 PM, Nate Duehr wrote:


On Jul 26, 2004, at 4:25 PM, Kilian Krause wrote:

Hi Dan,

until your ns1 goes down too, things should go fine. If you think, you
need to worry, watch the load on ns1. If that goes alarmingly up, then
things start going wrong (which is *very* unlikely to happen). If
however you desire to make sure your DNS is safe and accessible even in
case ns2 is not restored soon, setup a ns3 and have it listed in whois
and your zonefile.

Just a small technical point on this one... what's in the whois makes no difference. You need to get it into the GTLD servers as an A-record (i.e. register it as one of your nameservers) but most registrar's whois data lags far behind the GTLD server records. I can understand where your idea comes from that it would have to go in whois... registering it as a nameserver means the registrar will eventually put it in whois, but DNS resolvers don't look at whois and don't care what's in the whois servers, ultimately they look only at the GTLD servers.

dig @a.gtld-servers.net <domainname> ns

... is the only authoritative way to see what the registrar is handing out for your zone after you send in the registration change. If the records have changed/updated there and haven't made it into whois yet, it doesn't matter from the perspective of the DNS resolvers out there.

And then there's caching to deal with...

Follow-up for those reading along. Kilian's talking about a .de domain and I (like a bumbling idiot) said "GTLD servers" -- of course, the top-level DNS servers for .de are not gtld-servers.net -- sigh.

Kilian and I were talking about this off-line, but just so there's no confusion on the list... replace gtld-servers.net with the appropriate top-level domain servers for your domain suffix.

Easiest way to figure it out is to start at the root servers and work your way down...

dig @a.root-servers.net <domain> ns

You'll get back the response or you'll get a referral to the next level down...

Wheeee.... DNS.

--
Nate Duehr, nate@natetech.com



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