Your pattern does match 0.0.0.0 from what I can tell. And this slight change makes it robust against arbitrary prefix zeros to boot. 
/^
   0*?(?:1?\d\d?|2[0-4]\d|25[0-5])\.
   0*?(?:1?\d\d?|2[0-4]\d|25[0-5])\.
   0*?(?:1?\d\d?|2[0-4]\d|25[0-5])\.
   0*?(?:1?\d\d?|2[0-4]\d|25[0-5])
$/x;

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--- demerphq
my friends call me, usually because I'm late....

In reply to Re: Re: IP Address Sanity by demerphq
in thread IP Address Sanity by Anonymous Monk

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