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CCENT

Instructions:

Answer 50 questions in 15 minutes.
If you are not ready to take this test, you can study here.
Match each statement with the correct term.
Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.

This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.

1. Name the OSI Layers
/9
(7)Application -(6)Presentation -(5)Session -(4)Transport - (3)Network - (2)Data Link - (1)Physical
Closest multiple of the magic number that is not over the interesting octets number.
Switch forwards frame once it completely receives it

2. Subnetting: How many hosts per network if the subnet mask is 255.255.255.128
126 per network
Pins 1+2 swap places with pins 3+6
R
Router(config)#hostname R1 - R1(config)#line VTY 0 4 - R1(config-line)#login local - R1(config-line)#transport input telnet ssh - R1(config-line)#exit - R1(config)#username {user} password {pass} - R1(config)#ip domain-name {domainname} - R1(config)#

3. Subnetting: How many hosts per network if the subnet mask is 255.255.255.192
62 per network
255.255.255.128
Shortest path first - (SPF)
Every 8 ip's

4. RIP Timers: What is an invalid Timer?
F an update has not been received to refresh an existing route after 180 seconds (the default) - the route is marked as invalid by setting the metric to 16. The route is retained in the routing table until the flush timer expires.
/9
Packets
255.255.192.0

5. RIP Timers: What is an Flush Timer?
Application
R1(config)#int s0/0 - R1(config-inf)clock rate 64000 <-- on the DCE
By default - the flush timer is set for 240 seconds - which is 60 seconds longer than the invalid timer. When the flush timer expires - the route is removed from the routing table.
Interface changes state (up/down) - A route has entered or exited the unreachable state - a route was installed in the routing table.

6. Rip and EIGRP use what to keep other routers aware of their status?
Add the magic number to the network minus 1
Periodic Updates of their routing table
60
120

7. Switching Methods: What is Cut-through?
This timer stabilizes routing information and helps prevent routing loops during periods when the topology is converging on new information. Once a route is marked as unreachable - it must stay in holddown long enough for all routers in the topology
Switch forwards the frame as soon as it can
Every 64 ip's
R1(config)#int s0/0 - R1(config-inf)clock rate 64000 <-- on the DCE

8. Subnetting: What is a /18 in Decimal
Physical
Every 16 ip's
IEEE 802.3
255.255.192.0

9. EIGRP: What is the range of Autonomous System numbers?
1-65535
IEEE 802.3ab
30 per network
Multicast packet used for discovery of neighbors sent every 5 seconds - on WAN links sent every 60 seconds

10. What is the boot sequence for Cisco Routers?
IEEE 802.3u
255.255.0.0
1. NVRAM - 2. Flash (sequential) - 3. TFTP server (network boot) - 4. ROM (partial IOS)
/24

11. Symbol for Rip on a Show ip route
Interface changes state (up/down) - A route has entered or exited the unreachable state - a route was installed in the routing table.
Presentation
R
Router(config)# router rip - Router(config-router)# passive-interface fa0/0

12. EIGRP: What packet is used to propagate routing information?
Use command bandwidth {bandwidth in KPS} or the command ip ospf cost {amount} both in the interface you want to change
It adds the cost of each jump - R1 to R2 over a t1 is a cost of 64 - R2 to computer is a cost of 1. Total cost of route is 65
Can be multicast or unicast depending on number of routers - Update packets. Responds with an ACK packet
The metric is called cost - and refers to the speed of the port - IE 56kps = 1785 where Fast Ethernet = 1

13. What is the Transport PDU called?
1:O/W - 2:Orange - 3:G/W - 4:Blue - 5:B/W - 6:Green - 7:Brown/W - 8:Brown
Segments
IEEE 802.3z
R1(config)# router OSPF 1 - R1(config-router)#network 10.1.1.0 0.0.0.15 area 0

14. OSPF: How does OSPF calulate the cost of each route - to figure out which way to go?
/22
Every 16 ip's
It adds the cost of each jump - R1 to R2 over a t1 is a cost of 64 - R2 to computer is a cost of 1. Total cost of route is 65
IEEE 802.3z

15. What are the comands to set the clock rate in a serial connection?
R1(config)#int s0/0 - R1(config-inf)clock rate 64000 <-- on the DCE
Router(config)#ip route {exit-interface}
110
Segments

16. EIGRP: What packet is used to search for networks?
Hop Count
Query and other router responds with a REPLY packet.
180
2 - each port is it's own collision domain

17. Symbol for EIGRP on a Show ip route
DCE
D
Data-Link
Every 64 ip's

18. Using the magic number how to you figure the broadcast?
Every 128 ip's
Bandwidth - Delay - reliability and Load
Add the magic number to the network minus 1
IEEE 802.3u

19. What is Layer 3 in the OSI Model?
110
Interface changes state (up/down) - A route has entered or exited the unreachable state - a route was installed in the routing table.
Network
255.255.255.128

20. What is the metric for RIP
/24
Bandwidth - Delay - reliability and Load
Application
Hop Count

21. RIP Timers: What is an Holddown Timer?
This timer stabilizes routing information and helps prevent routing loops during periods when the topology is converging on new information. Once a route is marked as unreachable - it must stay in holddown long enough for all routers in the topology
Every 16 ip's
Use command bandwidth {bandwidth in KPS} or the command ip ospf cost {amount} both in the interface you want to change
DCE

22. Command for a static route with 'Next Hop' Address
Data-Link
It adds the cost of each jump - R1 to R2 over a t1 is a cost of 64 - R2 to computer is a cost of 1. Total cost of route is 65
Router(config)#ip route {network address} {subnet-mask}
1. Router receives update from neighbor indicating a route down - Router makes route as down and starts holddown timer - If router gets an update indicating route is back holddown is removed - If an update is received indicating route is down again i

23. Subnetting: What is a /27 in Decimal
/9
Network
255.255.255.224
Show ip eigrp topology

24. OSPF: Commands to enable OSPF area 0 and advertise network 10.1.1.1 /28
Use command bandwidth {bandwidth in KPS} or the command ip ospf cost {amount} both in the interface you want to change
Data-Link
R1(config)# router OSPF 1 - R1(config-router)#network 10.1.1.0 0.0.0.15 area 0
Switch forwards the frame as soon as it can

25. EIGRP: What is the name of the algorithm used for EIGRP?
DUAL: Difusing Update Algorithm
IEEE 802.3ab
Bandwidth - Delay - reliability and Load
Show ip eigrp topology

26. Rip: What does v2 have that v1 does not?
Includes sub-net mask in updates making it classless - has authentication - supports variable length subnet mask - uses multicast instead of broadcast - supports manual summarization
120
Data-Link
/24

27. What gets the clock rate - DCE or DTE?
Router(config)#hostname R1 - R1(config)#line VTY 0 4 - R1(config-line)#login local - R1(config-line)#transport input telnet ssh - R1(config-line)#exit - R1(config)#username {user} password {pass} - R1(config)#ip domain-name {domainname} - R1(config)#
Bandwidth - Delay - reliability and Load
DCE
Packets

28. IEEE Standards: Gibabit Ethernet (Fibre)
Periodic Updates of their routing table
R3(config)#router rip - R3(config-router)#network 192.168.1.2
Network
IEEE 802.3z

29. Rip: What is the command to enable Ripv2?
1:O/W - 2:Orange - 3:G/W - 4:Blue - 5:B/W - 6:Green - 7:Brown/W - 8:Brown
Periodic Updates of their routing table
R1(config)#router rip - R1(config-router)#version 2
Network

30. IEEE Standards: Gibabit Ethernet (Copper)
2 - each port is it's own collision domain
Segments
IEEE 802.3ab
180

31. Subnetting: What is a 255.255.252.0 in prefix notation
R1(config)# router OSPF 1 - R1(config-router)#network 10.1.1.0 0.0.0.15 area 0
/22
1:O/W - 2:Orange - 3:G/W - 4:Blue - 5:B/W - 6:Green - 7:Brown/W - 8:Brown
Bandwidth - Delay - reliability and Load

32. OSPF: What is the process used by OSPF to build a routing table (step by step)
1:G/W - 2:Green - 3:O/W - 4:Blue - 5:B/W - 6:Orange - 7:Brown/W - 8:Brown
1. Discovery packets - LSP built containing the state of each link - Flood LSP to neighbors - Build Link-state database
2 - the bridge separates the collision domain
255.255.255.224

33. Subnetting: where do the networks break with a /27

34. EIGRP: What is the default administrative distance?
Packets
The metric is called cost - and refers to the speed of the port - IE 56kps = 1785 where Fast Ethernet = 1
100
110

35. IEEE Standards: Fast Ethernet
126 per network
IEEE 802.3z
Multicast packet used for discovery of neighbors sent every 5 seconds - on WAN links sent every 60 seconds
IEEE 802.3u

36. What is Layer 5 in the OSI Model?
Multicast packet used for discovery of neighbors sent every 5 seconds - on WAN links sent every 60 seconds
1 - everything hooked to the hub is in the same collision domain
Every 8 ip's
Session

37. EIGRP: What is the hello packet used for?
R3(config)#router rip - R3(config-router)#network 192.168.1.2
Segments
Frames
Multicast packet used for discovery of neighbors sent every 5 seconds - on WAN links sent every 60 seconds

38. Rip Timers: How long is the default for Holddown timer.
180
Transport
2 - the bridge separates the collision domain
126 per network

39. Subnetting: where do the networks break with a /26

40. CABLES: What is the difference between T568A and T568B?
IEEE 802.3u
/9
Pins 1+2 swap places with pins 3+6
2 hosts

41. Subnetting: What is a /16 in Decimal
It adds the cost of each jump - R1 to R2 over a t1 is a cost of 64 - R2 to computer is a cost of 1. Total cost of route is 65
255.255.0.0
Data-Link
110

42. What Layer does CDP operate at?
/9
Bandwidth - Delay - reliability and Load
Layer 2
Segments

43. Rip Timers: How long is the default for Flush timer.
60
/22
F an update has not been received to refresh an existing route after 180 seconds (the default) - the route is marked as invalid by setting the metric to 16. The route is retained in the routing table until the flush timer expires.
100

44. What is the metric for EIGRP
120
Router(config)# router rip - Router(config-router)# passive-interface fa0/0
Bandwidth - Delay - reliability and Load
R1(config)#int s0/0 - R1(config-inf)clock rate 64000 <-- on the DCE

45. EIGRP: What is the commands to enable EIGRP for autonomous area 7 and to route network 192.168.1.0 /30
Shortest path first - (SPF)
/28
R1(config)#router eigrp 7 - R1(config-router)#network 192.168.1.0 0.0.0.3
Presentation

46. What is the layer 4 PDU called?
R
2 hosts
Segments
Data-Link

47. How do you find the magic number for subnetting?
R1(config)#router rip - R1(config-router)#version 2
R
14 per network
256 - the interesting (non-255/0) number. IE: 255.240.0.0 the interesting number is 240

48. Subnetting: How many hosts per network if the subnet mask is 255.255.255.252
2 hosts
Show ip eigrp topology
Multicast packet used for discovery of neighbors sent every 5 seconds - on WAN links sent every 60 seconds
This timer stabilizes routing information and helps prevent routing loops during periods when the topology is converging on new information. Once a route is marked as unreachable - it must stay in holddown long enough for all routers in the topology

49. Subnetting: What is a 255.255.255.0 in prefix notation
255.255.0.0
Use command bandwidth {bandwidth in KPS} or the command ip ospf cost {amount} both in the interface you want to change
Interface changes state (up/down) - A route has entered or exited the unreachable state - a route was installed in the routing table.
/24

50. OSPF: how do you change the cost of an interface for OSPF?
Every 128 ip's
Interface changes state (up/down) - A route has entered or exited the unreachable state - a route was installed in the routing table.
255.255.255.128
Use command bandwidth {bandwidth in KPS} or the command ip ospf cost {amount} both in the interface you want to change