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2.0 Switching and Network Access

CDP & LLDP Practice Questions

Cisco Discovery Protocol and the vendor-neutral LLDP.

CCNA v2.0 objective 2.3 · objective map

Author-reviewed by LabFabric · 6 September 2026 · Report a content issue

One solved question, so you can see how these are marked

Which command summarizes neighbors currently learned through CDP, including the local interface and advertised remote port?

show cdp neighbors

show cdp neighbors summarizes the CDP cache, not every physically connected device. A neighbor must advertise CDP to be learned, and a cached entry can remain until its holdtime expires after a disconnect. Correlate discovery output with interface state.

Every question in the set below is marked like this. The answers stay hidden until you pick one.

Find related practice in the CCNA path
All 6 CDP & LLDP questions in this set

Answers and explanations appear when you work through the set above.

  1. Which command filters detailed CDP output to the neighbor whose device ID is R2, including any advertised IP address?

    • show cdp neighbors detail
    • show cdp entry R2
    • show ip cdp R2
    • show cdp interface R2

  2. A switch has two ports facing end-user PCs and several ports facing other switches. To stop advertising CDP information toward the PCs only, while keeping CDP running on the switch itself, what should be configured?

    • no cdp run in global configuration mode
    • no cdp enable on each interface connected to a PC
    • no cdp advertise-v2 globally
    • shutdown on the PC-facing interfaces

  3. A network administrator disables CDP entirely on a switch and wants to use the vendor-neutral equivalent instead, with transmit and receive both explicitly enabled on the uplink interface. Which set of commands is correct?

    • cdp disable, then int g0/1, then cdp transmit and cdp receive
    • no cdp run, then lldp run, then int g0/1, then lldp transmit and lldp receive
    • lldp run globally is enough; no interface commands are needed
    • no lldp run, then cdp enable, then int g0/1, then lldp transmit

  4. Which statement correctly distinguishes CDP from LLDP?

    • CDP is an IEEE open standard, while LLDP is Cisco proprietary
    • CDP is Cisco proprietary, while LLDP (IEEE 802.1AB) is vendor-neutral and designed for multi-vendor interoperability
    • CDP operates at Layer 3 while LLDP operates at Layer 2
    • LLDP cannot advertise IP address information, but CDP can

  5. The network diagram shows SW1 Gi1/0/24 connected to R1 Gi0/1. On SW1, show cdp neighbors lists R1 on local interface Gi1/0/23 with port ID Gi0/1, and users report no problems. An AI assistant recommends moving the cable to Gi1/0/24 to match the diagram. What is the best response?

    • Move the cable at once, because the diagram is the authoritative source
    • Ignore the CDP output, because CDP cache entries are frequently out of date
    • Treat the diagram as inaccurate, confirm the intended port, and update the documentation
    • Shut down Gi1/0/23 so that CDP rediscovers R1 on the documented port

  6. Documentation says SW2 Gi0/2 connects to a third-party firewall. The interface is up/up, but show cdp neighbors shows nothing on Gi0/2. Which step best validates the documentation?

    • Enable LLDP with lldp run and check show lldp neighbors, since the firewall likely does not speak CDP
    • Conclude that the firewall is disconnected, because an up/up port always has a CDP neighbor
    • Increase the CDP holdtime so that the firewall has more time to appear in the cache
    • Run show cdp traffic to see the firewall's hostname and management address