If you're dealing with IPv6 addresses check out the Net::IP module for bringing them to the canonical form and other operations.

$ perl -l
use Net::IP;
my $ip = new Net::IP("FD02:3539:700B:1::FE");
print $ip->ip();
^D
fd02:3539:700b:0001:0000:0000:0000:00fe
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