And then there are wildcard DNS records. Try the above code (assuming the script is called "resolve") with: 
$ perl resolve www.startpagina.nl

[download]
which gives: 
www.startpagina.nl is www.startpagina.nl
        addr #0 is [62.69.162.8]
        addr #1 is [62.69.162.6]
        addr #2 is [62.69.162.7]

[download]
All nice and good, you would say. You get 3 IP-numbers and it resolves back correctly. Now you want to find all the aliases to "www.startpagina.nl". Try this by doing: 
$ perl resolve anythingyoucanthinkof.startpagina.nl

[download]
which generates this output: 
anythingyoucanthinkof.startpagina.nl is anythingyoucanthinkof.startpag
+ina.nl
        addr #0 is [62.69.162.7]
        addr #1 is [62.69.162.8]
        addr #2 is [62.69.162.6]
        That addr reverses to host www.startpagina.nl!

www.startpagina.nl is www.startpagina.nl
        addr #0 is [62.69.162.8]
        addr #1 is [62.69.162.6]
        addr #2 is [62.69.162.7]

[download]
Now replace "anythingyoucanthinkof" with anything else you can think of. Then meditate on the number of aliases "www.startpagina.nl" has. ;-)

Hope this helps.

Liz

In reply to Re: Re: Finding hostname aliases by liz
in thread Finding hostname aliases by marknm

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