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
