Subdomains need time to be resolvable

Virtualmin
#1

Hello,

I run into the following problem:

I create a lot of subdomain virtual servers (separate “master” virtual server, that is having subdomain.domain.tld as domain name). This is creating a separate master zone in the BIND DNS server config.

The problem is that the main domain is used pretty extensively and the subdomains are not resolvable from all the computers that have cached the zone for domain.tld. (They are working OK with dns testing tools)

The option “Add sub-domain DNS records to parent domain?” in the server template is set to Yes, but nothing is added to the parent domain zone (is this a bug?).

How can I make those subdomains to be resolvable immediately from everywhere?

Thanks in advance!

Operating system: CentOS Linux 5.8
Webmin version: 1.590
Virtualmin version: 3.94.gpl GPL

#2

OK, from what I discover, this is probably problem of Windows. Using nslookup to test the subdomains is working as expected - all subdomains resolve immediately. I will investigate more and post the result.

#3

For this kind of domain name resolvability (is that a word even? :wink: ) test, I recommend the tool dig which is part of the BIND package. E.g. dig example.com +trace will do a recursive query, starting at the DNS root servers and moving through DNS hierarchy down to the authoritative nameservers for the domain in question.

IF the domain is resolvable and propagated, this command will find that out and circumvent most intermediate caching or OS issues.

#4