DNS Free Tools

Cricket Liu's DNS advisor (external check)

Cricket Liu's DNS advisor Pro DNS Advisor Pro is the authoritative test for internal DNS

Men&Mice DNS Analyzing Service, Test your domain now  

Use DIG to view your domain in the internet 

Various Demon Internet tools

The most comlete WhoIS service 

Website finder

Perl DNS resolver, DNS is a DNS resolver implemented in Perl. It allows the programmer to perform nearly any type of DNS query from a Perl script

Vendors:

Infoblox

VitalQIP

Men & Mice

Introduction to DNS and more

How DNS works  

Wikipedia IPAM

DNS for rocket scientists but not for IPAM.NL menbers ;-)

Technology and Protocol:

IPv6Taskforce (Dutch chapter)

DNS, BIND, DHCP, LDAP and Directory Services

IPv6taskforce (Europe chapter)

DNSSEC

Organizations:

http://www.ietf.org/

http://nlnetlabs.nl/

http://www.iana.org/

http://www.ripe.net/

http://www.sidn.nl/

http://www.icann.org/

Books about DNS

O'Reilly DNS and BIND, The bible of DNS