You have good solutions for splitting your string, but do you have to normalize your ip string? As a hash key '192.168.0.1' ne '192.168.000.001'. The following may help:

my $ip = '192.168.0.1';
(my $ip_norm = $ip) =~ s/(\d+)/sprintf "%03d", $1/ge;

print "$ip | $ip_norm";
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Prints:

192.168.0.1 | 192.168.000.001
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