CDP & LLDP Flashcards

Cisco Discovery Protocol and Link-Layer Discovery Protocol

1
Q

What is the MAC address for CDP multicast messages?

A

0100.0CCC.CCCC

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2
Q

T/F: CDP is enabled on all Cisco devices by default

A

T

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3
Q

T/F: When a device receives a CDP message, it processes and discards the message (doesn’t forward)

A

T

CDP messages are never forwarded. Therefore, only adjacent neighbors can receive CDP messages from a device

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4
Q

T/F: When a device receives a CDP message, it forwards the message to other Cisco devices

A

F

CDP messages are never forwarded. Therefore, only adjacent neighbors can receive CDP messages from a device

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5
Q

What is the default CDP message interval?

A

60 seconds

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6
Q

What is the default CDP hold time

A

180 seconds

If a message isn’t received within this time frame, the neighbor is removed from the CDP table

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7
Q

T/F: There are 2 versions of CDP, and the default is V1

A

F

CDPv2 is the default

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8
Q

T/F: There are 2 versions of CDP, and the default is V2

A

T

CDPv2 is the default

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9
Q

Command to show CDP information such as version, holdtime, etc.

A

sh cdp

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10
Q

Command to show CDP neighbor information

A

sh cdp neighbors

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11
Q

Command to show CDP related traffic metrics, including packets I/O, errors, etc.

A

sh cdp traffic

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12
Q

Command to show CDP related information on interfaces

A

sh cdp interface

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13
Q

What command should you use to view the information in a Cisco device’s neighbor table?

A

sh cdp neighbors

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14
Q

Command to show verbose information on CDP neighbors

A

sh cdp neighbors detail

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15
Q

What CDP command should be used to identify a native VLAN mismatch?

A

sh cdp neighbors detail

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16
Q

What CDP command should be used to identify speed/duplex configuration mismatches?

A

sh cdp neighbors detail

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17
Q

What CDP command should be used to view verbose information about one CDP neighbor

A

sh cdp entry neighbor-hostname

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18
Q

What is the output of

sh cdp

A

Basic CDP information, including timers, version, etc.

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19
Q

What is the output of

sh cdp traffic

A

How many CDP messages have been sent and receives, and errors

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20
Q

What is the output of

sh cdp interface

A

Displays which interfaces CDP is enabled on, and related per-device information

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21
Q

What is the output of

sh cdp neighbors

A

Lists CDP neighbors and basic information about each neighbor, including hostname and what port they are connected to on both sides

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22
Q

What is the output of

sh cdp neighbors detail

A

Lists each CDP neighbor with verbose, detailed information

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23
Q

What is the output of

sh cdp entry hostname

A

Displays the same information as sh cdp neighbors detail, but for only the neighbor with the specified hostname

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24
Q

T/F: If running all Cisco devices and CDP use is desired, then configuration is required on each device

A

F

CDP is configured as necessary by default on all Cisco devices

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25
Q

Command to disable CDP on an entire device

A

from global config mode: no cdp run

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26
Q

Command to enable CDP, if it isn’t enabled already

A

from global config mode: cdp run

27
Q

Command to disable CDP on an interface

A

from interface config mode: no cdp enable

28
Q

Command to enable CDP on an interface, if it isn’t already

A

from interface config mode: cdp enable

29
Q

Command to adjust CDP message timer

A

from global config mode: cdp timer seconds

30
Q

Command to adjust CDP holdtime:

A

from global config mode: cdp holdtime seconds

31
Q

Command to enable/disable CDP V2

A

from global config mode: [no] cdp advertise-v2

32
Q

What is the IEEE standard for LLDP

A

IEEE 802.1AB

33
Q

T/F: LLDP is usually disabled on Cisco devices by default

A

T

34
Q

T/F: LLDP is usually enabled on Cisco devices by default

A

F

Must be configured for use on Cisco devices

35
Q

What is the multicast MAC address for LLDP

A

0180.C200.000E

36
Q

T/F: When a device receives an LLDP message, it processes it and discards it

A

T

37
Q

T/F: When a device receives an LLDP message, it processes it and forwards it

A

F

LLDP messages are discarded after being processed, so that only adjacent neighbors ever receive LLDP messages

38
Q

What is the default message timer for LLDP

A

30 seconds

39
Q

What is the default hold time for LLDP

A

120 seconds

40
Q

What is the default re-initialization delay for LLDP

A

2 seconds

41
Q

What is the purpose of the LLDP re-initialization timer

A

If LLDP is enabled either globally or on a specific interface, this timer will delay the actual initialization of LLDP.

This is to help in cases of flapping, where LLDP is rapidly disabled and re-enabled

This is likely not on the CCNA exam

42
Q

T/F: On Cisco devices, LLDP is usually disabled both globally and on each interface

A

T

43
Q

T/F: On Cisco devices, LLDP is usally enabled globally but disabled on each interface

A

F

LLDP is disabled globally and on each int by default

44
Q

T/F: On Cisco devices, LLDP is usually disabled globally but enabled on each interface

A

F

LLDP is disabled globally and on each int by default

45
Q

What is the command to enable LLDP globally on Cisco devices

A

lldp run

46
Q

What is the command to enable LLDP on an interface in the transmit direction

A

From interface config mode: lldp transmit

47
Q

What is the command to enable LLDP on an interface in the receive direction

A

From interface config mode: lldp receive

48
Q

What is the command to adjust the LLDP message timer

A

lldp timer <seconds></seconds>

49
Q

What is the command to adjust the LLDP hold timer

A

lldp holdtime <seconds></seconds>

50
Q

What is the command to adjust the LLDP re-init timer

A

lldp reinit <seconds></seconds>

51
Q

Command to show basic information about LLDP

A

sh lldp

52
Q

Command to show LLDP message counters and errors

A

sh lldp traffic

53
Q

Command to show which interfaces LLDP is operating on (tx or rx)

A

sh lldp interface

54
Q

Command to list LLDP neighbors and basic info on neighbors

A

sh lldp neighbors

55
Q

Command to show detailed information about LLDP neighbors

A

sh lldp neighbors detail

56
Q

Command to show detailed information for a single LLDP neighbor

A

sh lldp entry <hostname></hostname>

57
Q

What is shown by the following command:

sh lldp

A

Basic LLDP configuration information

58
Q

What is shown by the following command:

sh lldp traffic

A

LLDP message counters, including errors

59
Q

What is shown by the following command:

sh lldp interface

A

Which interfaces LLDP tx/rx is enabled on

60
Q

What is shown by the following command:

sh lldp neighbors

A

LLDP neighbors and basic information about each neighbor

61
Q

What is shown by the following command:

sh lldp neighbors detail

A

Detailed information about each LLDP neighbor

62
Q

What is shown by the following command:

sh lldp entry <hostname></hostname>

A

Detailed information about a single specified LLDP neighbor

63
Q

What command should be used to restore the LLDP hold timer configuration to its default value?

A

no lldp holdtime