5. Finally, design a stealthy-scan for SYN-ACK amplifiers, i.e., without sending any packet containing the source-IP of the scanner to the amplifier. Your solution may assume a number of known helper hosts as defined in previous items. Explain your design with a sequence diagram. Communication to the helper hosts (e.g. at 9.9.9.9) does not need to be stealthy, i.e., can use the scanner's IP address. Note: stealthy scans are sensitive to 'noise' (background traffic); in this question, you can assume there is no such 'noise', i.e., that the only packets sent are of the scan. 6. Show how you can modify the stealthy scan of the previous question to be robust to entities receiving and sending up to three packets not related to the scan ('noise')