Probabilistic Packet Marking is used in a network. Node B received 20 packets with the same source IP address, which is 10.3.2.30. Among them, 11 packets have IP address 10.0.2.24 in the marking field, 5 packets have IP 64.3.0.18 in that field, and 4 packets have no information there. Can you tell whether they are spoofed packets? If among them, ten packets with 12.0.2.24, six packets with 8.9.0.1, three packets with 1.2.3.4, and one packet with 33.24.11.7, can you tell whether they are spoofed packets? Bob thinks that using a lower overwrite probability, say, 30% instead of 50%, this technique can support IP Traceback with more intermediate routers. Do you agree with him? Why?

Convert and simplify the following sentences to conjunctive normal form (cnf): (a) (p → (q → r)) → (p → (r → q)) (b) (p ∧ q) → (¬p ↔ q) (c) ((p → q) ∧ ¬q) → ¬p

Write the command that can be used to answer the following questions. (hint: try each out on the system to check your results.) a. find all files on the system that have the word test" as part of their filename. b. search the path variable for the pathname to the awk command. c. find all files in the /usr directory and subdirectories that are larger than 50 kilobytes in size. d. find all files in the /usr directory and subdirectories that are less than 70 kilobytes in size. e. find all files in the / directory and subdirectories that are symbolic links. f. find all files in the /var directory and subdirectories that were accessed less than 60 minutes ago. g. find all files in the /var directory and subdirectories that were accessed less than six days ago. h. find all files in the /home directory and subdirectories that are empty. i. find all files in the /etc directory and subdirectories that are owned by the group bin."

Amitha writes up a one-page summary of a novel during her summer internship at a publishing company. when she reads over the page, she realizes she used the word “foreshadow” seven times, and she would like to reduce the repetition. which tool would best amitha solve this problem?