Al's CCNA Practice Test #3

Revised June 27, 2018

(If you find any errors, let me know!)

1. Which of the following prefixes summarizes only the networks in the range from through


2. Which of the following are advantages of link-state protocols?

  1. Depletes excess RAM
  2. Conserves bandwidth
  3. Rapid convergence
  4. Scalability using areas
  5. Expends spare CPU cycles

3. When designing an IP network, which types of traffic should be considered?

  1. Network management
  2. IP telephony
  3. IP Multicast
  4. Normal data
  5. Scavenger class
  6. All of the above.
  7. None of the above.

4. How can IPv6 addresses be assigned to hosts?

  1. Statically
  2. Stateful autoconfiguration
  3. DHCP
  4. All of the above.
  5. None of the above.

5. Who was the creator of the STP algorithm?

  1. Bellman
  2. Diffie
  3. Dijkstra
  4. Garcia-Luna-Aceves
  5. Hellman
  6. Metcalfe
  7. Perlman

6. With regard to IPv6, what is the meaning of "EUI"?

  1. Error Unit Installed
  2. Enhanced Ultimate IP
  3. Extensible User Indicator
  4. Extended Unique Identifier
  5. None of these.

7. Which of the following are routed protocols?

  1. IPv4
  2. IPX RIP
  3. OSPF
  4. IPv6
  5. EIGRP
  6. MP-BGP

8. Why would a router prefer an EIGRP route over a RIP route for the same prefix?

  1. Because EIGRP is a link-state protocol.
  2. Because EIGRP's admin distance of 90 is less than RIP's.
  3. Because RIP's admin distance of 110 is higher than EIGRP's.
  4. Because RIP is an exterior gateway protocol.
  5. Because Cisco protocols are superior to open-standard protocols.

9. Which of the following are advantages of voice VLANs?

  1. Reduced bandwidth usage.
  2. Enhanced security.
  3. Enhanced QoS.
  4. Enhanced consultant profit margins.
  5. All of the above.

10. What is covered by the summary route

  1. The subnets from through
  2. The subnets from through
  3. The subnets from through
  4. The networks through
  5. The networks from through

11. VLANs are identified by:

  1. Color
  2. Number
  3. Gender
  4. Smell

12. Which of the following support IPv6 routing?

  1. Static
  2. RIPv1
  3. RIPv2
  4. RIPng
  5. OSPFv2
  6. OSPFv3
  7. OSPFv6
  8. EIGRP
  9. IS-IS
  10. MP-BGP

13. When a frame gets caught in a Layer-2 loop, it's referred to as a:

  1. Handshaking hurricane
  2. Multicast monsoon
  3. Telnet tornado
  4. Broadcast storm

14. What is the allowable range of OSPF area numbers?

  1. "0", and only zero.
  2. 0 to 255
  3. 0 to 65,535
  4. to
  5. It depends on the vendor.

15. Which command configures open-standard Frame Relay on an interface?

  1. encapsulation frame-relay
  2. encapsulation frame-relay ietf
  3. encapsulation frame-relay open
  4. no encapsulation hdlc

16. What is the goal of route summarization?

  1. To reduce WAN costs.
  2. To conserve IP address space.
  3. To reduce IP routing overhead.
  4. To reduce serialization delay.
  5. To reduce calories.

17. Which of the following command sequences configures all ports of a twenty-four port switch to immediately shift into forwarding mode upon interface activation?

  1. Router1(config)#spanning-tree portfast default
  2. Router1(config)#interface range 0/1 - 24
    Router1(config-if-range)#spanning-tree portfast
  3. Router1(config)#no spanning-tree vlan 1
  4. Router1(config)#interface range 0/1 - 24
    Router1(config-if-range)#no spanning-tree vlan 1
  5. Since bypassing the STP algorithm will always result in a routing loop, this is not allowed.

18. How many total addresses are available with IPv4?

  1. 256
  2. 65,536
  3. 16,777,216
  4. Approximately four billion.
  5. Trillions and trillions!
  6. None of these.

19. For two switches to synchronize their VLAN databases via VTP, which of the following must be true?

  1. They must inhabit the same VTP domain.
  2. They must have the same VTP password.
  3. They must both be set to "transparent" mode.
  4. They must agree on the VTP password (if configured).
  5. They must be trunked.
  6. Neither must be in "transparent" mode.

20. What is covered by the prefix

  1. All subnets from through
  2. All subnets from through
  3. All subnets from through
  4. This is not a legal summary route.
  5. It is impossible to determine from the information available.

21. What range of VLANs is propagated by VTPv1?

  1. 0 to 1023
  2. 1 to 1023
  3. 1 to 4094
  4. 0 to 4095
  5. None of the above.

22. Which of the following describes EIGRP?

  1. Classical distance-vector
  2. Link-state
  3. Balanced hybrid (advanced distance-vector)
  4. Path-vector
  5. Open standard

23. Which of the following are disadvantages of link-state protocols?

  1. Require more RAM.
  2. Waste bandwidth.
  3. Slow convergence.
  4. Lack of scalability.
  5. Requires a pipelined CPU architecture.
  6. Strict network design rules.

24. Which of the following are in private address space?

  4. All of the above.
  5. None of the above.

25. A switch receives a frame with source and destination address of "FFFF-FFFF-FFFF". What does the switch do (and why)?

  1. Flood the frame and add the source address to the switching table (because switches flood broadcasts).
  2. Drop the frame (because it is illegal to have the broadcast address as a source address).
  3. Forward the frame to the broadcast-enabled hosts (because that's what the MAC address table tells them to do).
  4. Echo the frame back the way it came (because the sender must be confused).

26. EIGRP can load-share over a maximum of how many paths?

  1. 1
  2. 2
  3. 4
  4. 6
  5. 16
  6. 256
  7. 4094

27. If a switch has two equal-cost paths to the root, which interface does it choose?

  1. The even-numbered one.
  2. The one with the lowest MAC address.
  3. The one with the lowest interface ID.
  4. The one with the highest interface ID.
  5. The one with the lowest BPDU resynch interval.

28. Which of the following commands displays the number of EIGRP neighbors on an interface?

  1. show ip eigrp topology
  2. show ip eigrp neighbors
  3. show ip eigrp interfaces
  4. show ip eigrp

29. Which of the following are true concerning STP?

  1. One root bridge per broadcast domain.
  2. One designated port per segment.
  3. One root port per non-root bridge.
  4. Non-designated ports are blocked.
  5. All of the above.

30. Two routers are connected by a serial link running HDLC. In addtion to the WAN link, Router1 has three attached LANs, and Router2 has two attached LANs (a total of six subnets). The network has been subnetted using VLSM. The,, and subnets are already in use. Two additional subnets are required, one supporting 50 hosts, and another supporting 10 hosts. Which two of the following subnets will suffice?


31. If there are 10 VLANs, how many spanning trees will there be?

  1. One, if running Common Spanning Tree (CST).
  2. Ten, if running PVST+.
  3. Configurable from one to ten, if running MST.
  4. All of the above are true.
  5. None of the above are true.

32. Which type of NAT does the command "ip nat inside source list 1 pool test123" configure?

  1. Static
  2. PAT
  3. Dynamic
  4. GNAT
  5. Overloaded

33. Which protocol supports scalable port security?

  2. IEEE 802.1D
  3. IEEE 802.1X
  4. IEEE 802.11n
  5. IEEE 802.5

34. Who was the creator of the SPF algorithm?

  1. Bellman
  2. Diffie
  3. Dijkstra
  4. Garcia-Luna-Aceves
  5. Hellman
  6. Metcalfe
  7. Perlman

35. What controls the timers for STP?

  1. The root switch.
  2. The secondary root switch.
  3. The switch with the highest bridge ID.
  4. The switch with the most accurate clock.
  5. The switch that is connected to the router.

36. What are three benefits of VPNs?

  1. Lowered costs.
  2. Reduced routing overhead.
  3. Increased security.
  4. IP address conservation.
  5. Better scalability.

37. How is an "EUI-64" address determined?

  1. The MAC address is appended to the priority.
  2. The MAC address is subtended with the second integral of the square root of the router ID.
  3. The value 0xFFFE is inserted into the middle of the MAC address, and the "U" bit is set to "1".
  4. The value 0xEFFF is inserted into the middle of the MAC address, and the "G" bit is set to "1".
  5. It varies by manufacturer.

38. What is indicated by the "count to infinity"?

  1. The metrics are increasing due to a routing loop.
  2. The hold down timer is stuck in active.
  3. The flush timer failed to start.
  4. The feasible successor has staged a coup.
  5. Cisco stock has split yet again.

39. An enterprise has been assigned the address space, on which they are running EIGRP. Because they were running short of IPv4 addresses, and did not want to mess around with VLSM, they opted to use subnets of network (a private network) for their Frame Relay WAN links. Thus, they have subnets of one network on their LANs, and another network on the WAN. As soon as they made the change, routing ceased to function. What could be the problem, and what would you suggest as a solution?

  1. The problem is a discontiguous network, the solution is to turn off automatic route summarization under EIGRP.
  2. The problem is VLSM, the solution is to switch to a classful routing protocol.
  3. The problem is Inverse ARP, the solution is to disable Inverse ARP and use LMI instead.
  4. The problem is discontiguous subnets, the solution is to use a separate Class A network for each LAN.
  5. The problem is lack of bandwidth, the solution is to throw money at it.

40. What happens to the Frame Check Sequence when a frame is "dot1q" tagged?

  1. It is replaced by the VLAN ID.
  2. It is incremented by the VLAN ID.
  3. A new FCS is appended to the original FCS.
  4. It is replaced by a FCS calculated on the modified frame.
  5. It is randomized for security purposes.

41. Which of the following are advantages of a hierarchical addressing scheme?

  1. Fewer routing table entries.
  2. Reduced chance of configuration errors.
  3. Ease of management and troubleshooting.
  4. Significanty enhanced QoS for VoIP traffic.
  5. It permits overloaded NAT to be configured with only one command (Auto-NAT).

42. Three routers are connected in a full-mesh using Frame Relay with point-to-point subinterfaces. In addition to the WAN subnets, each router has two attached LANs. The address space has been allocated, and the following VLSM subnets are already in use:

Two additional subnets are required, one supporting 5 hosts, and another supporting 31 hosts. Which two of the following subnets will suffice?

43. What is the type code within an IEEE 802.1Q tag?

  1. 0x0800
  2. 0x0801
  3. 0x8100
  4. 0x8847

44. Going from most to least signicant bit, in what order are the fields of an IPv6 address arranged?

  1. Interface ID, Subnet, Site, ISP Prefix, Registry
  2. Registry, ISP Prefix, Site, Subnet, Interface ID
  3. Registry, Subnet, Site,ISP Prefix, Interface ID
  4. Network, Subnet, Host
  5. Host, Network, Subnet

45. What is the purpose of VTP pruning?

  1. To conserve bandwidth on uninvolved switches and links.
  2. To conserve CPU cycles on uninvolved hosts.
  3. To conserve RAM in the router-on-a-stick.
  4. To conserve the ozone layer.

46. How many total addresses are available with IPv6?

  1. 256
  2. 65,536
  3. 16,777,216
  4. 4,294,967,296
  5. Trillions and trillions!
  6. None of these.

47. Which of the following is useful for determing Layer-2 connectivity?

  1. CDP
  2. Ping
  3. Trace
  4. Telnet
  5. All of the above.

48. Which of the following authentication options are available with EIGRP?

  1. CIA
  2. MD5
  3. RSA
  4. Plaintext
  5. No authentication

49. Regarding the default STP timers, which of the following are true?

  1. Hello time is 10 seconds, dead time is 40 seconds, and max age is 3600 seconds.
  2. Hello interval is 2 seconds, forward delay is 15 seconds, and max age is 20 seconds.
  3. Hello interval is 20 seconds, forward delay is 15 seconds, and max age is 2 seconds.
  4. Hello interval is 15 seconds, forward delay is 20 seconds, and max age is 15 seconds.
  5. Advertisement interval is 30 seconds, hold down timer is 180 seconds, and flush timer is 240 seconds.

50. Given the following routing table (where the "P" column indicates the routing protocol), which entry is the best match for a packet destined for

P Destination        Next Hop          Outbound Interface
- -----------        --------          ------------------
R          Ethernet0/1
D    Serial2/1
C    Serial2/1
C          Ethernet0/1
O          Serial2/1
S    Serial2/1
  1. RIP route
  2. EIGRP route
  3. OSPF route
  4. Static route
  5. On-Demand route

Bonus Question: When an ACL denies a packet, the packet goes into the "bit bucket". How often should the privileged-mode command "clear ip bit-bucket" be executed?

  1. Every hour on the hour.
  2. Daily, whether it needs it or not.
  3. When it overflows.
  4. Never, the bit bucket empties automatically upon every spurious IOS software crash.
  5. You've got to be kidding me!


 1. C       11. B       21. B       31. D       41. ABC
 2. BCD     12. ADFHIJ  22. C       32. C       42. DE
 3. F       13. D       23. AF      33. C       43. C
 4. D       14. D       24. D       34. C       44. B
 5. G       15. B       25. B       35. A       45. A
 6. D       16. C       26. E       36. ACE     46. E
 7. AD      17. AB      27. C       37. C       47. E
 8. B       18. D       28. C       38. A       48. BE
 9. BC      19. ABDE    29. E       39. A       49. B
10. A       20. D       30. BD      40. D       50. B

Bonus Answer: E

5. Dr. Radia Perlman, and she worked for DEC at the time.
7. The others are "routing" protocols.
8. And RIP's default admin distance is 120.
12. RIPv1, RIPv2 and OSPFv2 are for IPv4, and there is no such thing as OSPFv6.
14. It's a 32-bit variable, and all values are legal.
15. The default Frame Relay encapsulation is a Cisco frame, if you want the IETF standard frame you have to say so.
20. Since "196" (the base address of the block) is not an even multiple of eight (the block size), this range of subnets cannot be summarized into one block.
21. Likewise for VTPv2.
25. No Ethernet interface should ever generate a frame with a non-unicast source address.
28. The "show ip eigrp neighbors" command displays which neighbors are on which interfaces, but you have to count them yourself to get the total number per interface.
30. "A" AND "C" both overlap with "E" overlaps with and "F" allows only six hosts, which is insufficient hosts for either of the two required subnets.
35. You can change the timers on any switch, but it won't have any immediate effect unless that switch is currently the root. If it's not the root, it's timers will control the switch cloud only if and when the switch becomes the root.
42. "A" overlaps with "B" overlaps with, 144/30, 148/30, 152/29 and 160/29. "C" overlaps with "F" supports 30 hosts, but since it overlaps with (which is required for the subnet that needs 50 hosts), it can't be used for the subnet requiring 5 hosts.
Bonus Question: A student in one of my CCNA Bootcamps asked how often the "bit bucket" should be emptied (and yes, he was serious!).

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