Time to (re-)read perlref and perllol.

Your $Stats{$Destport} is a hash value -- a scalar. That scalar can be a number, a string, or any other thing a scalar can hold, including a reference to another hash.

Think carefully about what you want to keep in your data structure. Possibly you need another key: $Stats{$Destport}{count}++;I can't tell if that's the right thing to do, since I'm not sure what the increment is doing.