CCNA 200-301 v1.1 reference — Network Access

CDP and LLDP

Layer 2 discovery protocols: enable and scope CDP and LLDP, read neighbor tables, and use detail output safely.

Objective 2.3v1.1 exam target

Property	CDP	LLDP
Standard	Cisco proprietary	IEEE 802.1AB (open)
Default on Cisco	Enabled globally, per-interface on	Disabled until `lldp run`
Timer / holdtime	60 s / 180 s	30 s / 120 s
TLVs	Device ID, port ID, platform, IP, native VLAN, duplex, VTP domain	Chassis/port ID, system name/desc, management address, capabilities
Use	Cisco-only estates	Mixed-vendor networks, IP phone voice-VLAN delivery

Values are platform defaults — verify against your device documentation.

Enable and scope LLDP

Enable LLDP globally and tune a port — Privileged EXEC → Global + interface configuration

Cisco IOS / IOS XE

configure terminal
lldp run
interface gigabitethernet1/0/24
 lldp transmit
 lldp receive
 end

Verify

show lldp neighbors
show lldp neighbors detail
show lldp

Changes device configuration.

$ show cdp neighbors (interpreted)

Capability Codes: R - Router, T - Trans Bridge, B - Source Route BridgeLetters reveal device function.

S - Switch, H - Host, I - IGMP, r - Repeater, P - PhoneP marks IP phones — voice VLAN verification.

Device ID Local Intrfce Holdtme Capability Platform Port IDLocal and remote port pair on each row.

SW2 Gig 1/0/24 158 S C9300 Gig 1/0/24SW2 reachable via its Gi1/0/24 from your Gi1/0/24.

SEP001A2B3C4D5E Gig 1/0/1 143 P IP Phone Port 1A phone — confirm it is in the voice VLAN.

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Targets CCNA 200-301 v1.1 objectives. Supplemental blocks are labeled beyond exam scope.