3.3.1. Cisco Discovery Protocol (CDP)

CDP is enabled by default on Cisco devices and shares:

• Device name and IP address
• Platform and capabilities
• Interface information
• VLAN information

Switch# show cdp neighbors
Capability Codes: R-Router, S-Switch, I-IGMP, r-Repeater, P-Phone

Device ID        Local Intrfce     Holdtme    Capability  Platform  Port ID
Router1          Gig 0/1           175             R S    ISR4331   Gig 0/0
Switch2          Gig 0/24          162              S     WS-C3850  Gig 0/24

Switch# show cdp neighbors detail    (more detailed output)
Switch# show cdp entry Router1       (specific neighbor)

CDP Configuration:

Switch(config)# cdp run                           ! Enable globally
Switch(config)# no cdp run                        ! Disable globally
Switch(config)# interface GigabitEthernet0/1
Switch(config-if)# no cdp enable                  ! Disable on interface