Domain Name Service And Virtual Hosting

1. DNS Resource Records

• A : a computer address - IP number
• NS : An authoritative name server - domain name for server
• CNAME : The canonical name for an alias - domain name for alias
• SOA : marks the start of data for a zone - parameters governing the zone
• WKS : a well-known service description - list of service names and protocols
• PTR : Domain name pointer (reverse lookups) - domain name
• HINFO : host information - machine architecture and operating system
  
• MX : mail exchange - list of <preference, host> pairs
• TXT : text string - arbitrary text

2. Server configuration

• resolver : DNS client
• entry : domain name, time to live, class, type, value
• 
  

• domain name	time to live	class	type	value	comments
  	1D	IN	NS	dns0	domain name server
  	1D	IN	NS	dns1	domain name server
  	1D	IN	NS	cancer.ucs.ed.ac.uk
  	1D	IN	MX	1 mail1.qmw.ac.uk
  	1D	IN	MX	2 mail2.qmw.ac.uk
  dns0	1D	IN	A	138.37....
  dns1	1D	IN	A	138.37....
  www	1D	IN	CNAME	copper
  copper	1D	IN	A	138.37.88.248
  dcs	1D	IN	NS	dns0.dcs	sub domain name server
  dns0.dcs	1D	IN	A	138.37.88.249
  dcs	1D	IN	NS	dns1.dcs	sub domain name server
  dns1.dcs	1D	IN	A	138.37.94.248
  dcs	1D	IN	NS	cancer.ucs.ed.ac.uk

3. BIND : The Berkeley Internet Name Domain

• an implementation of the DNS
• named (server process) and resolver (client library)
• three categories of name server : primary server, secondary server, caching-only server

4. dynamic updates on dns entry

• Dynamic DNS from DHCP
• djbdns
• DNS Configuration
• HOWTO: Registry Settings for the Microsoft DNS Server
• Windows NT Server Reference - DNS

5. wildcard domain

• How do I create a wildcard domain in DNS Manager?
• DNS wildcard records and virtual hosts
  

6. virtual hosting

• VirtualHost Examples
• mod_rewrite - Apache HTTP Server
• Apache 1.3 URL Rewriting Guide
• Name-based Virtual Hosts
• Apache Virtual Host documentation
• Dynamically configured mass virtual hosting

7. an Apache virtual host configuration example

#
# Use name-based virtual hosting.
#
NameVirtualHost ###.###.###.###

<VirtualHost ###.###.###.###>
#primary vhost
#         http://testie.test.com/blahblah => /test-domain/testie/blahblah (URI)
ServerName *.test.com
RewriteEngine On
RewriteCond      %{HTTP_HOST}        [^.]+\.test\.com$
RewriteRule      ^(.+)                %{HTTP_HOST}$1
RewriteRule      ([^.]+)\.test\.com(.*) /test-domain/$1$2
RewriteLog logs/rewrite.log
RewriteLogLevel 9
</VirtualHost>

<VirtualHost ###.###.###.###>
#secondary vhost
#     http://specific.javadom.com/blahblah => /home/javadom/blahblah (FILE PATH)
ServerName specific.javadom.com
#Redirect / http://specific.test.com/
RewriteEngine On
# $0 always means full token
RewriteRule (.*) /home/javadom/$1
RewriteLog logs/rewrite.log
RewriteLogLevel 9
</VirtualHost>

<VirtualHost ###.###.###.###>
#third vhost
#     http://baby.javadom.com/blahblah => /non-test-domain/baby.javadom.com/blahblah (URI)
ServerName *.javadom.com
RewriteEngine On
RewriteCond      %{HTTP_HOST}        !([^.]+\.test\.com$|specific\.javadom\.com)
RewriteRule      ^(.+)                %{HTTP_HOST}$1
RewriteRule      (.*)                /non-test-domain/$1
RewriteLog logs/rewrite.log
RewriteLogLevel 9
</VirtualHost>

8.