This is a variation of one from the Book "Mastering Regular Expressions" by Jeffrey Friedl, which I highly recommend. 
unless ( 
    $ip =~ m/^(?:[1]?\d\d?|2[0-4]\d|25[0-5])\.
              (?:[1]?\d\d?|2[0-4]\d|25[0-5])\.
              (?:[1]?\d\d?|2[0-4]\d|25[0-5])\.
              (?:[1]?\d\d?|2[0-4]\d|25[0-5])$
            /x
) 
{ 
    # do something 
}

[download]
Best Regards,
Wonko

In reply to Re: Validating IP Address by Wonko the sane
in thread Validating IP Address by SR

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