Which of the following is a system of notation that uses base 16 rather than base 10?

Internal users have been unable to access the web server on a local network that they are to use. qi have been to the help desk, and a technician has decided to apply the following commands to the equipment:
access-list 103 permit tcp any any eq 80
access-list 103 permit tcp any any eq 443
access-list 103 deny ip any any
On which of the following devices would the technician apply these commands?

Some similar devices are experiencing system crashes on the same day of every month. Which of the following is the MOST efficient approach to detect the probable cause of the recurring incidents?

Which of the following would be BEST for continually monitoring and alerting of possible attacks on a network?

Which of the following MUST be kept synchronized in order for Kerberos to work?