Homo-Adminus Blog

In one of my last posts about cheap hosting unlimited number of domains, I have described how to point your domain to some sub-directory of an existing hosting account. But sometimes hosting provider requires parking of your DNS name for creating aliases in hosting account. For example, hosting platform, created by me and used on Free Adult hosting Servik.com service, requires your domain’s NS-records to be directed to provider’s own DNS-servers. What can you do if you don’t want to park entire domain to provider’s DNS-servers and want to host only one sub-domain on its servers?

As a simple, but very powerful solution, I can suggest following trick.

Let’s see to generic DNS-domain configuration. Generic domain has following records:

• SOA – record with domain contact information, expiring values, etc.
• NS – record(s) with IP addresses of domain’s DNS-servers.
• MX – record(s) with IP or symbolic names of domain’s mail servers.
• A – record(s) with IP addresses of domain and subdomains.
• CNAME – synonyms for A-records.

When you asking your DNS system for resolving some symbolic name to an IP address and this name is some sub-domain name (such as kovyrin.net or mail.google.com), your DNS server trying to find NS-records for this sub-domain (e.g kovyrin.net) and then, if records were not found, it looks for NS servers for parent domain (kovyrin.net). With generic DNS configuration you can’t allow DNS-management of some sub-domain to off-site DNS-server. You can only move entire domain between DNS-servers.

But let’s try to add following records to your DNS-zone:

    ....
    subdomain.domain.com IN NS off-site.dns-server.com.
    ....

Now, all requests for subdomain.domain.com will be referred to off-site.dns-server.com and this server can freely manage delegated subdomain record by creating another sub-domains or changing this subdomain IP-address.

Some times we need to use our existing hosting account to (maybe temporarily) place another web-site in it. But what we can do, if our hosting provider allows only one hosting directory and only aliases for main site (as GoDaddy.com does)? We can use the following Apache+mod_rewrite trick to host unlimited number of domains on one hosting directory.

First of all, we need to point our new domain to hosting server IP. If server’s IP is static, we can do it by simple A-record in our DNS-zone control panel:

    new-domain.com  IN A IP.ADD.RE.SS

If you don’t know IP address of hosting server or this address is not permanent (for example, because of some load balancing used by hosting provider), you can use simple trick with CNAME-record in your new DNS-zone:

     new-domain.com  IN CNAME already-hosted-domain.com.

After the first step was finished we have new-domain.com pointed to our hosting provider’s server. Now, we need to add this domain support to hosting server. We can do it by your hosting provider’s “Domain aliases” option or another option with such meaning.

After we have associated our new domain name with existing directory on hosting server (/hosting/dir), everything we need is to do something to force hosting server to use some sub-directory for all requests to new-domain.com (/hosting/dir/new-domain). To do it, we need to put following code into the .htaccess file in /hosting/dir directory:

    RewriteEngine On
    RewriteBase /
    RewriteCond %{REQUEST_URI} !^/new-domain/
    RewriteCond %{HTTP_HOST} new-domain\.com$
    RewriteRule (.*) http://already-hosted-domain.com/new-domain/$1 [L]

That’s all! After we have created this file, all requests to new-domain.com will be pointed to /hosting/dir/new-domain directory.