+# Convenience for regex'
+# for tighter, see https://metacpan.org/dist/IO-Socket-IP/source/lib/IO/Socket/IP.pm#L37
+my $re_ipv4 = qr/\d{1,3}(?:\.\d{1,3}){3}/;
+my $re_6g = qr/[[:xdigit:]]{1,4}/;
+my $re_6s = qr/${re_6g}:/;
+my $re_ipv6 = qr/${re_6s}{0,7}${re_6g}(?:::${re_6s}{0,5}${re_6g})?/;
+my $re_ip = qr/(?:${re_ipv4}|${re_ipv6})/;
+