Taking the regex out of RE: Matching an IP address, which is from the MRE book, with a few small modifications, came up with this.

my @ips = ($string =~ m/((?:[01]?\d\d?|2[0-4]\d|25[0-5])\.(?:[01]?\d\d
+?|2[0-4]\d|25[0-5])\.(?:[01]?\d\d?|2[0-4]\d|25[0-5])\.(?:[01]?\d\d?|2
+[0-4]\d|25[0-5]))/g);
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Now @ips will have an array full of IP's, if they are valid or not is another discussion...