Command
CDP Enable
Use
This command is used to enable CDP on interfaces. By default it is enabled on most interfaces except for frame-relay interfaces.
Syntax
Router(config-if)#cdp enable
Example
In this example R1’s S1/1 interface is configured to authenticate R3 using PAP.
R1(config)#int fa0/0 R1(config-if)#cdp enable
Here we check the show cdp neighbor output to verify that it is working.
R2#show cdp neighbor Capability Codes: R – Router, T – Trans Bridge, B – Source Route Bridge S – Switch, H – Host, I – IGMP, r – Repeater Device ID Local Intrfce Holdtme Capability Platform Port ID R3 Fas 1/0 164 R S I 3640 Fas 0/0 R1 Fas 0/0 162 R S I 3640 Fas 0/0