15. How often are BPDUs sent from a layer 2 device?
A.Never
B.Every 2 seconds
C.Every 10 minutes
D.Every 30 seconds

---

16. How many broadcast domains are created when you segment a network with a 12-port switch?
A.1
B.2
C.5
D.12

---

17. What does the command routerA(config)#line cons 0 allow you to perform next?
A.Set the Telnet password.
B.Shut down the router
C.Set your console password.
D.Disable console connections.

---

18. Which router command allows you to view the entire contents of all access lists?
A.show all access-lists
B.show access-lists
C.show ip interface
D.show interface

---

19. Which class of IP address has the most host addresses available by default?
A.A
B.B
C.C
D.A and B

---

20. In a network with dozens of switches, how many root bridges would you have?
A.1
B.2
C.5
D.12

---

21. What PPP protocol provides dynamic addressing, authentication, and multilink?
A.NCP
B.HDLC
C.LCP
D.X.25

---