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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. EIGRP: What packet is used to propagate routing information?
Switch forwards frame once it completely receives it
D
Add the magic number to the network minus 1
Can be multicast or unicast depending on number of routers - Update packets. Responds with an ACK packet

2. EIGRP: What is the name of the algorithm used for EIGRP?
Bellman-Ford
DUAL: Difusing Update Algorithm
DCE
1:G/W - 2:Green - 3:O/W - 4:Blue - 5:B/W - 6:Orange - 7:Brown/W - 8:Brown

3. Command for a static route with 'Next Hop' Address
Router(config)#ip route {network address} {subnet-mask}
R3(config)#router rip - R3(config-router)#network 192.168.1.2
255.255.255.224
60

4. Switching Methods: What is Cut-through?
(7)Application -(6)Presentation -(5)Session -(4)Transport - (3)Network - (2)Data Link - (1)Physical
IEEE 802.3
Every 4 ip's
Switch forwards the frame as soon as it can

5. EIGRP: What is the hello packet used for?
Multicast packet used for discovery of neighbors sent every 5 seconds - on WAN links sent every 60 seconds
30 per network
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.
256 - the interesting (non-255/0) number. IE: 255.240.0.0 the interesting number is 240

6. How many Collision domains are there on a with 1 hub and 2 computers?
Router(config)#ip route {network address} {subnet-mask}
1 - everything hooked to the hub is in the same collision domain
Multicast packet used for discovery of neighbors sent every 5 seconds - on WAN links sent every 60 seconds
Add the magic number to the network minus 1

7. What gets the clock rate - DCE or DTE?
Router(config)# router rip - Router(config-router)# passive-interface fa0/0
(7)Application -(6)Presentation -(5)Session -(4)Transport - (3)Network - (2)Data Link - (1)Physical
255.255.255.224
DCE

8. Subnetting: What is a 255.255.255.240 in prefix notation
IEEE 802.3u
/28
R3(config)#router rip - R3(config-router)#network 192.168.1.2
126 per network

9. OSPF: What is the process used by OSPF to build a routing table (step by step)
R1(config)#int s0/0 - R1(config-inf)clock rate 64000 <-- on the DCE
Bandwidth - Delay - reliability and Load
14 per network
1. Discovery packets - LSP built containing the state of each link - Flood LSP to neighbors - Build Link-state database

10. What is the metric for EIGRP
Periodic Updates of their routing table
Bandwidth - Delay - reliability and Load
Interface changes state (up/down) - A route has entered or exited the unreachable state - a route was installed in the routing table.
D

11. RIP Timers: What is an Holddown Timer?
Closest multiple of the magic number that is not over the interesting octets number.
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
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.
D

12. RIP: What Algorithm is used in RIP>
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
Bellman-Ford
255.255.255.252
255.255.0.0

13. IEEE Standards: Ethernet
Every 16 ip's
1 - everything hooked to the hub is in the same collision domain
IEEE 802.3
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

14. Name the OSI Layers
Data-Link
Every 128 ip's
Shortest path first - (SPF)
(7)Application -(6)Presentation -(5)Session -(4)Transport - (3)Network - (2)Data Link - (1)Physical

15. Subnetting: How many hosts per network if the subnet mask is 255.255.255.224
100
30 per network
/22
Switch forwards frame after receiving the 1st 64bytes to insure no errors.

16. CABLES: What is the T568B Pinout Standard?
2 hosts
Every 64 ip's
1:O/W - 2:Orange - 3:G/W - 4:Blue - 5:B/W - 6:Green - 7:Brown/W - 8:Brown
126 per network

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

18. Subnetting: What is a 255.128.0.0 in prefix notation
2 - the bridge separates the collision domain
2 - each port is it's own collision domain
/9
1. Discovery packets - LSP built containing the state of each link - Flood LSP to neighbors - Build Link-state database

19. 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
D
Router(config)#ip route {exit-interface}
255.255.255.224

20. Name the TCP/IP Layers
(5)Application - (4)Transport - (3)Internet - (2)Data-Link - (1)Physical
DCE
Application
1. Discovery packets - LSP built containing the state of each link - Flood LSP to neighbors - Build Link-state database

21. Rip: Command to prevent rip updates on an interface
Router(config)# router rip - Router(config-router)# passive-interface fa0/0
Every 16 ip's
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.
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

22. Rip Timers: How long is the default for Holddown timer.
Frames
180
Packets
R1(config)#router rip - R1(config-router)#version 2

23. Subnetting: How many hosts per network if the subnet mask is 255.255.255.240
14 per network
Multicast packet used for discovery of neighbors sent every 5 seconds - on WAN links sent every 60 seconds
R1(config)#router eigrp 7 - R1(config-router)#network 192.168.1.0 0.0.0.3
2 - each port is it's own collision domain

24. EIGRP: What is the commands to enable EIGRP for autonomous area 7 and to route network 192.168.1.0 /30
Frames
1:G/W - 2:Green - 3:O/W - 4:Blue - 5:B/W - 6:Orange - 7:Brown/W - 8:Brown
R1(config)#router eigrp 7 - R1(config-router)#network 192.168.1.0 0.0.0.3
Application

25. Rip: how do hold down timers work?
DCE
Periodic Updates of their routing table
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
255.255.255.224

26. Using the magic number how to you figure the broadcast?
Add the magic number to the network minus 1
Can be multicast or unicast depending on number of routers - Update packets. Responds with an ACK packet
Packets
2 - each port is it's own collision domain

27. Subnetting: where do the networks break with a /25

28. Rip: What does v2 have that v1 does not?
Segments
Includes sub-net mask in updates making it classless - has authentication - supports variable length subnet mask - uses multicast instead of broadcast - supports manual summarization
Add the magic number to the network minus 1
1. NVRAM - 2. Flash (sequential) - 3. TFTP server (network boot) - 4. ROM (partial IOS)

29. RIP Timers: What is an Flush Timer?
Every 16 ip's
1:G/W - 2:Green - 3:O/W - 4:Blue - 5:B/W - 6:Orange - 7:Brown/W - 8:Brown
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.
IEEE 802.3ab

30. What are the commands to setup SSH?
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)#
IEEE 802.3
1-65535
DCE

31. What is the layer 4 PDU called?
Interface changes state (up/down) - A route has entered or exited the unreachable state - a route was installed in the routing table.
Show ip eigrp topology
Segments
Add the magic number to the network minus 1

32. What is the layer 2 PDU called?
R1(config)#router rip - R1(config-router)#version 2
Can be multicast or unicast depending on number of routers - Update packets. Responds with an ACK packet
14 per network
Frames

33. Subnetting: where do the networks break with a /28

34. Subnetting: What is a /25 in Decimal
255.255.255.128
Periodic Updates of their routing table
Show ip eigrp topology
256 - the interesting (non-255/0) number. IE: 255.240.0.0 the interesting number is 240

35. IEEE Standards: Gibabit Ethernet (Fibre)
1. Discovery packets - LSP built containing the state of each link - Flood LSP to neighbors - Build Link-state database
Transport
The metric is called cost - and refers to the speed of the port - IE 56kps = 1785 where Fast Ethernet = 1
IEEE 802.3z

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

37. Rip Timers: How long is the default for Flush timer.
/24
60
R1(config)#int s0/0 - R1(config-inf)clock rate 64000 <-- on the DCE
Periodic Updates of their routing table

38. RIP: What is the default Administrative Distance?
Show ip eigrp topology
R1(config)#router eigrp 7 - R1(config-router)#network 192.168.1.0 0.0.0.3
120
DCE

39. How do you find the magic number for subnetting?
(7)Application -(6)Presentation -(5)Session -(4)Transport - (3)Network - (2)Data Link - (1)Physical
R1(config)# router OSPF 1 - R1(config-router)#network 10.1.1.0 0.0.0.15 area 0
256 - the interesting (non-255/0) number. IE: 255.240.0.0 the interesting number is 240
2 - each port is it's own collision domain

40. What is Layer 6 in the OSI Model?
R1(config)#int s0/0 - R1(config-inf)clock rate 64000 <-- on the DCE
Every 64 ip's
14 per network
Presentation

41. EIGRP: What is the default administrative distance?
100
Every 64 ip's
Multicast packet used for discovery of neighbors sent every 5 seconds - on WAN links sent every 60 seconds
Frames

42. Rip and EIGRP use what to keep other routers aware of their status?
2 - the bridge separates the collision domain
Periodic Updates of their routing table
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
Use command bandwidth {bandwidth in KPS} or the command ip ospf cost {amount} both in the interface you want to change

43. OSPF: What does OSPF use for its metric?
The metric is called cost - and refers to the speed of the port - IE 56kps = 1785 where Fast Ethernet = 1
Shortest path first - (SPF)
2 hosts
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.

44. Using the magic number how to you figure the network?
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)#
Every 16 ip's
Pins 1+2 swap places with pins 3+6
Closest multiple of the magic number that is not over the interesting octets number.

45. OSPF: Commands to enable OSPF area 0 and advertise network 10.1.1.1 /28
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.
Every 32 ip's
R1(config)# router OSPF 1 - R1(config-router)#network 10.1.1.0 0.0.0.15 area 0
Router(config)# router rip - Router(config-router)# passive-interface fa0/0

46. RIP Timers: What is an invalid Timer?
30 per network
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.
180
1. Discovery packets - LSP built containing the state of each link - Flood LSP to neighbors - Build Link-state database

47. How many Collision domains are there on a with 1 hub and 1 bridge 2 computers?
1-65535
Every 64 ip's
2 - the bridge separates the collision domain
Switch forwards the frame as soon as it can

48. Symbol for EIGRP on a Show ip route
Add the magic number to the network minus 1
D
110
Can be multicast or unicast depending on number of routers - Update packets. Responds with an ACK packet

49. Subnetting: How many hosts per network if the subnet mask is 255.255.255.192
62 per network
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
R1(config)#router rip - R1(config-router)#version 2
Every 16 ip's

50. Command for a static route with exit interface
110
60
(7)Application -(6)Presentation -(5)Session -(4)Transport - (3)Network - (2)Data Link - (1)Physical
Router(config)#ip route {exit-interface}