44 - 238 CCNA 2: Routers and Routing Basics v3.1 Instructor Guide – Module 4 Copyright © 2004, Cisco Systems, Inc.
Command Purpose
clear cdp table Deletes information about neighbors from the CDP
table
clear cdp counters Reset traffic counters to zero
show cdp traffic Displays CD counters such as the number of
packets sent and received and checksum errors
show debugging Displays information about the types of debugging
that are enabled for the router
debug cdp adjacency Displays CDP neighbor information
debug cdp events Displays CDP events
debug cdp ip Displays CDP IP information
debug cdp packets Displays CDP packet-related information
cdp timers Specifies how often the Cisco IOS software sends
CDP updates
cdp holdtime Specifies the hold time to be sent in the
CDP update packet
show cdp Displays global CDP information such as timer and
hold-time information
Review the following key points:
CDP is Cisco proprietary.
CDP runs on any SNAP-enabled media.
CDP functions at Layer 2 and functions independent of the upper layers.
CDP is used by all Cisco network devices such as routers, switches, and bridges.
CDP utilizes periodic advertisements to obtain or update information about
directly-connected devices
Have students perform the CDP neighbor lab.
Web Links
http://www.cisco.com/univercd/cc/td/doc/product/software/ios121/121cgcr/fun_r/frprt3/frd3001b
.htm