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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. OSPF: Commands to enable OSPF area 0 and advertise network 10.1.1.1 /28
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)#
2 hosts
Data-Link
R1(config)# router OSPF 1 - R1(config-router)#network 10.1.1.0 0.0.0.15 area 0

2. Subnetting: where do the networks break with a /30

3. What is the Data-Link PDU called?
Periodic Updates of their routing table
Includes sub-net mask in updates making it classless - has authentication - supports variable length subnet mask - uses multicast instead of broadcast - supports manual summarization
Frames
1. NVRAM - 2. Flash (sequential) - 3. TFTP server (network boot) - 4. ROM (partial IOS)

4. Rip: how do hold down timers work?
180
1:O/W - 2:Orange - 3:G/W - 4:Blue - 5:B/W - 6:Green - 7:Brown/W - 8:Brown
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
Router(config)# router rip - Router(config-router)# passive-interface fa0/0

5. Rip and EIGRP use what to keep other routers aware of their status?
126 per network
Periodic Updates of their routing table
Data-Link
180

6. What is the layer 2 PDU called?
/22
R
R3(config)#router rip - R3(config-router)#network 192.168.1.2
Frames

7. Command for a static route with exit interface
Switch forwards the frame as soon as it can
14 per network
2 - each port is it's own collision domain
Router(config)#ip route {exit-interface}

8. Subnetting: How many hosts per network if the subnet mask is 255.255.255.192
R3(config)#router rip - R3(config-router)#network 192.168.1.2
62 per network
Hop Count
Show ip eigrp topology

9. Switching Methods: What is Store and Forward?
DUAL: Difusing Update Algorithm
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.
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
Switch forwards frame once it completely receives it

10. IEEE Standards: Gibabit Ethernet (Fibre)
IEEE 802.3z
Network
Layer 2
180 seconds

11. Rip Timers: How long is the default for Invalid timer.
2 - the bridge separates the collision domain
180 seconds
Every 64 ip's
Switch forwards frame once it completely receives it

12. EIGRP: What is the hello packet used for?
126 per network
Network
Multicast packet used for discovery of neighbors sent every 5 seconds - on WAN links sent every 60 seconds
/28

13. Rip: What does v2 have that v1 does not?
DUAL: Difusing Update Algorithm
Includes sub-net mask in updates making it classless - has authentication - supports variable length subnet mask - uses multicast instead of broadcast - supports manual summarization
Closest multiple of the magic number that is not over the interesting octets number.
R

14. EIGRP: What is the commands to enable EIGRP for autonomous area 7 and to route network 192.168.1.0 /30
R1(config)#router eigrp 7 - R1(config-router)#network 192.168.1.0 0.0.0.3
Router(config)# router rip - Router(config-router)# passive-interface fa0/0
Every 8 ip's
1 - everything hooked to the hub is in the same collision domain

15. Subnetting: What is a 255.128.0.0 in prefix notation
/9
IEEE 802.3
Every 32 ip's
126 per network

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

17. What is the Network PDU called?
Packets
Every 64 ip's
1:O/W - 2:Orange - 3:G/W - 4:Blue - 5:B/W - 6:Green - 7:Brown/W - 8:Brown
Transport

18. Subnetting: How many hosts per network if the subnet mask is 255.255.255.240
Show ip eigrp topology
1:G/W - 2:Green - 3:O/W - 4:Blue - 5:B/W - 6:Orange - 7:Brown/W - 8:Brown
Bandwidth - Delay - reliability and Load
14 per network

19. Subnetting: What is a /30 in Decimal
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.
30 per network
1:O/W - 2:Orange - 3:G/W - 4:Blue - 5:B/W - 6:Green - 7:Brown/W - 8:Brown
255.255.255.252

20. Name the OSI Layers
(7)Application -(6)Presentation -(5)Session -(4)Transport - (3)Network - (2)Data Link - (1)Physical
IEEE 802.3u
/9
Switch forwards the frame as soon as it can

21. Name the TCP/IP Layers
Hop Count
255.255.255.224
(5)Application - (4)Transport - (3)Internet - (2)Data-Link - (1)Physical
Show ip eigrp topology

22. What are the commands to setup SSH?
IEEE 802.3
62 per network
DUAL: Difusing Update Algorithm
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)#

23. How many Collision domains are there on a with 1 hub and 2 computers?
1 - everything hooked to the hub is in the same collision domain
/28
Periodic Updates of their routing table
2 - each port is it's own collision domain

24. EIGRP: What packet is used to propagate routing information?
14 per network
(7)Application -(6)Presentation -(5)Session -(4)Transport - (3)Network - (2)Data Link - (1)Physical
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

25. CABLES: What is the T568B Pinout Standard?
120
Pins 1+2 swap places with pins 3+6
/28
1:O/W - 2:Orange - 3:G/W - 4:Blue - 5:B/W - 6:Green - 7:Brown/W - 8:Brown

26. Command for a static route with 'Next Hop' Address
Router(config)#ip route {exit-interface}
Router(config)#ip route {network address} {subnet-mask}
Every 16 ip's
1:G/W - 2:Green - 3:O/W - 4:Blue - 5:B/W - 6:Orange - 7:Brown/W - 8:Brown

27. RIP: What Algorithm is used in RIP>
Bellman-Ford
Router(config)#ip route {exit-interface}
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.
1:O/W - 2:Orange - 3:G/W - 4:Blue - 5:B/W - 6:Green - 7:Brown/W - 8:Brown

28. EIGRP: What is the range of Autonomous System numbers?
Every 128 ip's
Can be multicast or unicast depending on number of routers - Update packets. Responds with an ACK packet
Periodic Updates of their routing table
1-65535

29. Subnetting: What is a /16 in Decimal
Router(config)# router rip - Router(config-router)# passive-interface fa0/0
Closest multiple of the magic number that is not over the interesting octets number.
255.255.0.0
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

30. What is the metric for RIP
Bellman-Ford
Hop Count
Includes sub-net mask in updates making it classless - has authentication - supports variable length subnet mask - uses multicast instead of broadcast - supports manual summarization
Session

31. Subnetting: How many hosts per network if the subnet mask is 255.255.255.128
30 per network
126 per network
IEEE 802.3z
110

32. Switching Methods: What is Fragment-free?
Use command bandwidth {bandwidth in KPS} or the command ip ospf cost {amount} both in the interface you want to change
/9
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 frame after receiving the 1st 64bytes to insure no errors.

33. RIP Timers: What is an Flush Timer?
Data-Link
60
1 - everything hooked to the hub is in the same collision domain
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.

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

35. Subnetting: What is a 255.255.255.240 in prefix notation
1 - everything hooked to the hub is in the same collision domain
/28
Session
Bellman-Ford

36. CABLES: What is the difference between T568A and T568B?
Pins 1+2 swap places with pins 3+6
Application
255.255.0.0
Bellman-Ford

37. What gets the clock rate - DCE or DTE?
255.255.255.128
1:G/W - 2:Green - 3:O/W - 4:Blue - 5:B/W - 6:Orange - 7:Brown/W - 8:Brown
The metric is called cost - and refers to the speed of the port - IE 56kps = 1785 where Fast Ethernet = 1
DCE

38. What is the boot sequence for Cisco Routers?
256 - the interesting (non-255/0) number. IE: 255.240.0.0 the interesting number is 240
IEEE 802.3u
1. NVRAM - 2. Flash (sequential) - 3. TFTP server (network boot) - 4. ROM (partial IOS)
Periodic Updates of their routing table

39. Subnetting: where do the networks break with a /29

40. OSPF: how do you change the cost of an interface for OSPF?
Switch forwards frame once it completely receives it
Use command bandwidth {bandwidth in KPS} or the command ip ospf cost {amount} both in the interface you want to change
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 64 ip's

41. OSPF: What is the process used by OSPF to build a routing table (step by step)
Physical
Every 64 ip's
1. Discovery packets - LSP built containing the state of each link - Flood LSP to neighbors - Build Link-state database
The metric is called cost - and refers to the speed of the port - IE 56kps = 1785 where Fast Ethernet = 1

42. OSPF: What Algorithm is used?
IEEE 802.3u
30 per network
Shortest path first - (SPF)
110

43. Subnetting: What is a 255.255.252.0 in prefix notation
/22
110
255.255.255.128
R1(config)#int s0/0 - R1(config-inf)clock rate 64000 <-- on the DCE

44. Switching Methods: What is Cut-through?
110
R1(config)#router eigrp 7 - R1(config-router)#network 192.168.1.0 0.0.0.3
Switch forwards the frame as soon as it can
DUAL: Difusing Update Algorithm

45. What is Layer 3 in the OSI Model?
2 hosts
Network
180 seconds
(7)Application -(6)Presentation -(5)Session -(4)Transport - (3)Network - (2)Data Link - (1)Physical

46. What is Layer 6 in the OSI Model?
180
IEEE 802.3z
Segments
Presentation

47. OSPF: What does OSPF use for its metric?
R
The metric is called cost - and refers to the speed of the port - IE 56kps = 1785 where Fast Ethernet = 1
Can be multicast or unicast depending on number of routers - Update packets. Responds with an ACK packet
Layer 2

48. What is the metric for EIGRP
Every 64 ip's
2 hosts
Bandwidth - Delay - reliability and Load
1-65535

49. How many Collision domains are there on a with 1 hub and 1 bridge 2 computers?
2 - the bridge separates the collision domain
DCE
IEEE 802.3ab
Query and other router responds with a REPLY packet.

50. What is the layer 4 PDU called?
R3(config)#router rip - R3(config-router)#network 192.168.1.2
DUAL: Difusing Update Algorithm
Segments
255.255.255.224