CDP Enable Command on CISCO Router/Switch


CDP Enable


This command is used to enable CDP on interfaces. By default it is enabled on most interfaces except for frame-relay interfaces.


Router(config-if)#cdp enable


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