Task 4 . The permission bits associated with a program call Prog 1 and a dataset called Data1 are as follows: Prog1: 111110000 Data1: 111101101 a) State the permissions these bits give. b) Describe the advantages and disadvantages of using permission bits for access control. Task 5. Define the configuration for a firewall, which should provide security at the Internet connection of a data centre according to the following demands. Access via HTTP (port B0) must be rejected from everywhere, while HTTPs (port 443) shall be allowed. ICMP requests and access via SSH (port 22) shall be accepted only from IP 193.94.80.15. Access via Teinet (port 23) is only allowed from IP 193.94.90.8, while a network administrator shall be notified in case of other Telnet connection attempts. All other incoming connections not matching one of the rules shall be dropped. The following actions are known: DENY, DROP, REJECT, ALLOW, FORWARD, NOTIFY