DNS "IN NS" Record questions (and load balancing)

DukeLeto · 04-04-2008, 07:16 PM

Dear LQ,

I'm considering setting up GSLB (global server load balancing) with DNS (and am well aware of the caveats).

Let's say I have domain 1234.com

I have nameservers (which I don't really have much control over) that are:

ns1.serviceprovider.com
ns2.serviceprovider.com

which my 1234.com domain uses.

If I set up a zone file that looked similar to this (on the serviceprovider.com ns servers):

Code:

$ORIGIN .
$TTL 900        ; 15 minutes
1234.com IN SOA ns1.1234.com.
support@1234.com. (
                                2007111301 ; serial
                                10800      ; refresh (3 hours)
                                900        ; retry (15 minutes)
                                604800     ; expire (1 week)
                                900        ; minimum (15 minutes)
                                )
                        NS      ns1.1234.com.
                        NS      ns2.1234.com.
                        NS      ns3.1234.com.
ns1                     A       1.1.1.1
ns2                     A       1.1.1.2
ns3                     A       3.1.1.2

What I'm hoping to accomplish is although the domain is set up to use ns1/2.serviceprovider.com, actual a record lookups will then go to ns1.1234.com, etc.

The bind9 running on ns1-3 of 1234.com would actually have a custom geodns patch, allowing views broken down as fine grained as state. I would have my zone files on ns1-3 of 1234.com with the actual a and mx records.

Is this possible?

In summary, here's what I want to accomplish:

Client does this....

Client(looking for www.1234.com)--->ns1.serviceprovider.com (which returns ns1.1234.com as authorative for the domain)--->Client--->ns1.1234.com(returns A record of 1.1.1.3 for www)

Am I off base or is this possible?

Thanks,
Michael

scowles · 04-05-2008, 08:20 AM

Have never tried the GeoDNS stuff, but from a recursion standpoint, the example shown above should work. Basically, all you are doing is delegating the SOA for 1234.com to another DNS server. This is not any different than delegating a sub-domain of 1234.com to another DNS server within the 1234.com zone file. The syntax would be the same. eg. In the 1234.com zone file, add a NS record for sub-domain.1234.com that points to the DNS server that is authoritative for the sub-domain.

If this does not work, I guess you can always change your domain registration to point to your DNS servers directly.

BTW: I did some research on the GoeDNS patch. I ened up at the GeoIP website and typed in one of my public IP's. Pretty scary. The info returned even had my area code along with a #$%^%$ google map <groan!> But this finally explains how a website like abc.com can display the local ABC affiliate logo in my area when viewing a TV show.

JimBass · 04-05-2008, 01:06 PM

You can't change the resolution by doing anything other than changing the authoritative servers. You can't just add an ns3 in the zone and have it queried by anything. The way a server is queried is only if it is on the list of authoritative servers. Your authoritative server can't designate another.

So if you can't get ns3 on the authoritative list at the registrar's site, it will never be queried.

Peace,
JimBass