Cisco Discovery Protocol (CDP)

RouterA#
RouterA# sh cdp
Global CDP information:
Sending CDP packets every 60 seconds
Sending a holdtime value of 180 seconds
RouterA#config t
Enter configuration commands, one per line. End with CNTL/Z.
RouterA(config)# cdp timer ?
<5-900> Rate at which CDP packets are sent (in sec)

RouterA(config)# cdp timer 90
RouterA(config)#^Z
RouterA#
%SYS-5-CONFIG_I: Configured from console by consolesh 
RouterA#

RouterA# sh cdp 
Global CDP information:
Sending CDP packets every 90 seconds
Sending a holdtime value of 180 seconds

RouterA# sh cdp ?
entry Information for specific neighbor entry
interface CDP interface status and configuration
neighbors CDP neighbor entries
traffic CDP statistics
<cr>

RouterA# sh cdp int
Ethernet0 is up, line protocol is up
Encapsulation ARPA
Sending CDP packets every 90 seconds
Holdtime is 180 seconds
Serial0 is up, line protocol is up
Encapsulation HDLC
Sending CDP packets every 90 seconds
Holdtime is 180 seconds
Serial1 is administratively down, line protocol is down
Encapsulation HDLC
Sending CDP packets every 90 seconds
Holdtime is 180 seconds
RouterA#
RouterA# sh cdp entry RouterB
-------------------------
Device ID: RouterB
Entry address(es): 
IP address: 172.16.20.2
Platform: cisco 2500, Capabilities: Router 
Interface: Serial0, Port ID (outgoing port): Serial0
Holdtime : 146 sec

Version :
Cisco Internetwork Operating System Software 
IOS (tm) 2500 Software (C2500-JS-L), Version 11.2(18), RELEASE SOFTWARE (fc1)
Copyright (c) 1986-1999 by cisco Systems, Inc.
Compiled Mon 05-Apr-99 20:23 by jaturner

RouterA#
RouterA# show cdp neighbors 
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
005050E3FEC0 Eth 0 149 T S 1900 3 
RouterB Ser 0 134 R 2500 Ser 0
RouterA#