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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: how do you change the cost of an interface for OSPF?
Use command bandwidth {bandwidth in KPS} or the command ip ospf cost {amount} both in the interface you want to change
1-65535
255.255.192.0
Every 16 ip's

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

3. OSPF: What Algorithm is used?
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.
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)#
1. Discovery packets - LSP built containing the state of each link - Flood LSP to neighbors - Build Link-state database
Shortest path first - (SPF)

4. Subnetting: What is a 255.255.255.0 in prefix notation
(5)Application - (4)Transport - (3)Internet - (2)Data-Link - (1)Physical
/28
Hop Count
/24

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

6. What Layer does CDP operate at?
DUAL: Difusing Update Algorithm
Interface changes state (up/down) - A route has entered or exited the unreachable state - a route was installed in the routing table.
Layer 2
Closest multiple of the magic number that is not over the interesting octets number.

7. Rip Timers: How long is the default for Holddown timer.
Can be multicast or unicast depending on number of routers - Update packets. Responds with an ACK packet
180
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
/9

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

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

10. Rip Timers: How long is the default for Invalid timer.
180 seconds
Frames
R1(config)#router rip - R1(config-router)#version 2
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)#

11. Symbol for Rip on a Show ip route
255.255.192.0
R
1:G/W - 2:Green - 3:O/W - 4:Blue - 5:B/W - 6:Orange - 7:Brown/W - 8:Brown
180

12. What is the metric for EIGRP
2 - the bridge separates the collision domain
IEEE 802.3z
Bandwidth - Delay - reliability and Load
Hop Count

13. How many Collision domains are there on a with 1 hub and 1 bridge 2 computers?
126 per network
2 - the bridge separates the collision domain
255.255.255.224
255.255.255.252

14. EIGRP: What is the hello packet used for?
Bellman-Ford
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
Multicast packet used for discovery of neighbors sent every 5 seconds - on WAN links sent every 60 seconds
DUAL: Difusing Update Algorithm

15. Rip and EIGRP use what to keep other routers aware of their status?
R
Switch forwards frame after receiving the 1st 64bytes to insure no errors.
Application
Periodic Updates of their routing table

16. What is Layer 2 in the OSI Model?
The metric is called cost - and refers to the speed of the port - IE 56kps = 1785 where Fast Ethernet = 1
Data-Link
Layer 2
IEEE 802.3u

17. 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
Router(config)#ip route {exit-interface}
1 - everything hooked to the hub is in the same collision domain
Packets

18. What is the layer 4 PDU called?
/9
Multicast packet used for discovery of neighbors sent every 5 seconds - on WAN links sent every 60 seconds
Segments
Packets

19. Rip: Command to prevent rip updates on an interface
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.
Router(config)# router rip - Router(config-router)# passive-interface fa0/0
255.255.192.0

20. Subnetting: How many hosts per network if the subnet mask is 255.255.255.224
1-65535
Bellman-Ford
30 per network
Network

21. OSPF: What is the process used by OSPF to build a routing table (step by step)
Application
D
Frames
1. Discovery packets - LSP built containing the state of each link - Flood LSP to neighbors - Build Link-state database

22. Command for a static route with exit interface
Segments
Presentation
Router(config)#ip route {exit-interface}
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. CABLES: What is the T568B Pinout Standard?
IEEE 802.3
Session
1:O/W - 2:Orange - 3:G/W - 4:Blue - 5:B/W - 6:Green - 7:Brown/W - 8:Brown
1. Discovery packets - LSP built containing the state of each link - Flood LSP to neighbors - Build Link-state database

24. Subnetting: How many hosts per network if the subnet mask is 255.255.255.192
62 per network
Layer 2
Presentation
1-65535

25. IEEE Standards: Ethernet
IEEE 802.3
Frames
1. Discovery packets - LSP built containing the state of each link - Flood LSP to neighbors - Build Link-state database
Bandwidth - Delay - reliability and Load

26. Subnetting: What is a /27 in Decimal
255.255.192.0
IEEE 802.3
(7)Application -(6)Presentation -(5)Session -(4)Transport - (3)Network - (2)Data Link - (1)Physical
255.255.255.224

27. IEEE Standards: Fast Ethernet
IEEE 802.3u
D
R
Router(config)# router rip - Router(config-router)# passive-interface fa0/0

28. What is Layer 6 in the OSI Model?
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 4 ip's
Bellman-Ford
Presentation

29. EIGRP: How do you view if there are any successor routes?
Application
R1(config)#router eigrp 7 - R1(config-router)#network 192.168.1.0 0.0.0.3
Show ip eigrp topology
Segments

30. OSPF: What does OSPF use for its metric?
R3(config)#router rip - R3(config-router)#network 192.168.1.2
D
1:O/W - 2:Orange - 3:G/W - 4:Blue - 5:B/W - 6:Green - 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

31. RIP: What is the default Administrative Distance?
/9
Every 64 ip's
Can be multicast or unicast depending on number of routers - Update packets. Responds with an ACK packet
120

32. What is the Network PDU called?
Packets
Use command bandwidth {bandwidth in KPS} or the command ip ospf cost {amount} both in the interface you want to change
The metric is called cost - and refers to the speed of the port - IE 56kps = 1785 where Fast Ethernet = 1
30 per network

33. Subnetting: How many hosts per network if the subnet mask is 255.255.255.252
255.255.0.0
2 hosts
R
R1(config)# router OSPF 1 - R1(config-router)#network 10.1.1.0 0.0.0.15 area 0

34. IEEE Standards: Gibabit Ethernet (Copper)
/9
Switch forwards frame after receiving the 1st 64bytes to insure no errors.
IEEE 802.3ab
/28

35. Subnetting: How many hosts per network if the subnet mask is 255.255.255.128
Every 16 ip's
126 per network
1-65535
D

36. RIP: What Algorithm is used in RIP>
Bellman-Ford
Transport
Router(config)#ip route {exit-interface}
IEEE 802.3z

37. EIGRP: What packet is used to search for networks?
Interface changes state (up/down) - A route has entered or exited the unreachable state - a route was installed in the routing table.
DCE
Query and other router responds with a REPLY packet.
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

38. What gets the clock rate - DCE or DTE?
/9
Periodic Updates of their routing table
R1(config)#router rip - R1(config-router)#version 2
DCE

39. RIP: Commands to enable ripv1 on a router and add a route to 192.168.1.2
Every 128 ip's
R3(config)#router rip - R3(config-router)#network 192.168.1.2
Bellman-Ford
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.

40. Switching Methods: What is Store and Forward?
2 - the bridge separates the collision domain
Transport
Segments
Switch forwards frame once it completely receives it

41. How many Collision domains are there on a with 1 switch 2 computers?

42. EIGRP: What is the commands to enable EIGRP for autonomous area 7 and to route network 192.168.1.0 /30
2 - the bridge separates the collision domain
/28
R1(config)#router eigrp 7 - R1(config-router)#network 192.168.1.0 0.0.0.3
1. NVRAM - 2. Flash (sequential) - 3. TFTP server (network boot) - 4. ROM (partial IOS)

43. EIGRP: What is the range of Autonomous System numbers?
Use command bandwidth {bandwidth in KPS} or the command ip ospf cost {amount} both in the interface you want to change
Every 8 ip's
1-65535
Router(config)#ip route {exit-interface}

44. 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.
255.255.0.0
IEEE 802.3u
/9

45. Command for a static route with 'Next Hop' Address
62 per network
Router(config)#ip route {network address} {subnet-mask}
Router(config)# router rip - Router(config-router)# passive-interface fa0/0
DUAL: Difusing Update Algorithm

46. Subnetting: What is a /16 in Decimal
255.255.0.0
30 per network
Presentation
1:G/W - 2:Green - 3:O/W - 4:Blue - 5:B/W - 6:Orange - 7:Brown/W - 8:Brown

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

48. OSPF: What is the default administrative distance?
110
IEEE 802.3z
Presentation
Show ip eigrp topology

49. How do you find the magic number for subnetting?
Pins 1+2 swap places with pins 3+6
R1(config)# router OSPF 1 - R1(config-router)#network 10.1.1.0 0.0.0.15 area 0
1:G/W - 2:Green - 3:O/W - 4:Blue - 5:B/W - 6:Orange - 7:Brown/W - 8:Brown
256 - the interesting (non-255/0) number. IE: 255.240.0.0 the interesting number is 240

50. Name the TCP/IP Layers
IEEE 802.3
Segments
180
(5)Application - (4)Transport - (3)Internet - (2)Data-Link - (1)Physical