public void excludeAddress(String low_ip, String high_ip){
        boolean found = false;
        for(int i=0; i<exclude.size() && !found; i++){
            Pair el = exclude.get(i);
            if(el.getFirst().equals(low_ip) && el.getSecond().equals(high_ip)){
                found = true;
            }
        }
        if(!found){
            exclude.add(new Pair(low_ip, high_ip));
        }
    }