Detecting a non-existent domain

Jack Bates jbates at brightok.net
Tue Sep 23 21:37:57 UTC 2003


Kee Hinckley wrote:

> 
> Getting practical for a minute.  What is the optimal way now to see if a 
> given host truly exists?  Assume that I can't control the DNS server--I 
> need to have this code run in any (*ix) environment. Assume also that I 
> don't want to run around specialcasing specific IP addresses or 
> TLDs--this needs to work reliably no matter what the domain.  User gives 
> me a string, and I need to see if the given host is a real machine.
> 

A set comparison between the domain your interested in and *.TLD will 
inform you if the domain is pointed to the same IP addresses as the 
wildcard. In many cases, this is sufficient and can be made to work 
dynamically and quickly with most software and scripts.

-Jack




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