CDP Flashcards
What does CDP stand for?
Cisco Discovery Protocol.
What does CDP display?
Physically-connected devices, including their hostname, device model, management IP, and connecting interfaces.
What is the industry-standard version of CDP?
LLDP, the link-layer discovery protocol.
Why is CDP a security concern?
It provides detailed network information and sends all information in clear-text.
What are the default CPD timers?
A hello timer of 60 seconds and a hold timer of 180 seconds.
Can CDP be enabled/disabled globally?
Yes, and it can also be enabled/disabled at the interface level.
In addition to device information, what else can CDP detect?
VLAN mismatches, MTU size, and PoE levels.
What does CDP stand for?
Cisco Discovery Protocol.
What is CDP?
CDP is a Cisco Proprietary feature that allows you to see directly connected Cisco devices. It is also used for other communication like POE negotiation.
What does LLDP stand for?
Link Layer Discovery Protocol.
What is LLDP?
LLDP is industry standard and not proprietary. Allows you to see directly connected hosts.
Is LLDP enabled by default?
LLDP is not enabled by default. LLDP is turned on with a similar command to CDP, lldp run.
How to disable CDP?
Globally Switch(config)#no cdp run per Interface Switch(config)#no cdp enable
Adjust the advertisement interval and holdtime:
cdp timer cdp holdtime
Disable CDPv2 advertisements globally:
no cdp advertise-v2
Disable logging of duplex mismatches for Ethernet interfaces globally or at the interface:
no cdp log mismatch duplex
Specify a source interface for CDP advertisements to ensure CDP reports the desired IP address to neighbors:
cdp source-interface
Secure CDP Configuration (cli)
Globally create TLV list: cdp tlv-list name Add the TLVs you wish to filter out to the list, such as ip-prefix or hello-protocol Apply the filter list either globally or at the interface level: cdp filter-tlv-list name Filter lists applied at the interface take precedence over lists applied globally
Display global CDP information including timers and v2 status:
show cdp
Display information about a specific CDP neighbor (or all neighbors by using *):
show cdp entry {* | device-id}
Display L2 encapsulation type and timers of individual interfaces:
show cdp interface [interface]
Display information about detected neighbors:
show cdp neighbors [detail] The detail keyword is similar to show cdp entry and displays more information about the CDP neighbors
Display the current CDP counters:
show cdp traffic
Display the contents of the CDP TLV-list:
show cdp tlv-list
Reset the statistics gathered by CDP:
clear cdp counters
Remove all neighbors from the CDP neighbor table. Neighbors will be re-discovered during their next advertisement interval.
clear cdp table
When should CDP be enabled?
only for trusted Cisco gear, especially phones
Which statement about Cisco Discovery Protocol configuration on a Cisco switch is true?
CDP is enabled by default and can be disabled globally with the command no cdp run.
A network engineer notices inconsistent Cisco Discovery Protocol neighbors according to the diagram that is provided. The engineer notices only a single neighbor that uses Cisco Discovery Protocol, but it has several routing neighbor relationships. What would cause the output to show only the single neighbor?
The routers are connected via a Layer 2 switch.
After the implementation of several different types of switches from different vendors, a network engineer notices that directly connected devices that use Cisco Discovery Protocol are not visible. Which vendor-neutral protocol could be used to resolve this issue?
Link Layer Discovery Protocol
While doing network discovery using Cisco Discovery Protocol, it is found that rapid error tracking is not currently enabled. Which option must be enabled to allow for enhanced reporting mechanisms using Cisco Discovery Protocol?
Cisco Discovery Protocol version 2
A network engineer has just deployed a non-Cisco device in the network and wants to get information about it from a connected device. Cisco Discovery Protocol is not supported, so the open standard protocol must be configured. Which protocol does the network engineer configure on both devices to accomplish this?
LLDP
Which statement about Cisco devices learning about each other through Cisco Discovery Protocol is true?
Each device sends periodic advertisements to multicast address 01:00:0C:CC:CC:CC.
Which option lists the information that is contained in a Cisco Discovery Protocol advertisement?
native VLAN IDs, port-duplex, hardware platform
Which statement about LLDP-MED is true?
LLDP-MED is an extension to LLDP that operates between endpoint devices and network devices.
Which option describes a limitation of LLDP?
LLDP cannot provide information about VTP.
What is the default interval at which Cisco devices send Cisco Discovery Protocol advertisements?
60 seconds
What is the default interval at which Cisco devices send Cisco Discovery Protocol advertisements?
A. 30 seconds
B. 60 seconds
C. 120 seconds
D. 300 seconds
B. 60 Sec.
