Convert elements of @blocklist,and the "one IP address", into NetAddr::IP objects.
Those objects support the method:

$me->contains($other) 
  #Returns true when $me completely contains $other. False is returned
+ otherwise
  # and undef is returned if $me and $other are of different versions.

  #Note that $me and $other must be NetAddr::IP objects.
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You can then use grep to filter the list of objects, limiting them to thost where the condition is TRUE.