Specifications

10-2
System Management Software Configuration Guide for Cisco IE 2000U and Connected Grid Switches
Chapter 10 Configuring CDP
Prerequisites
The switch supports CDP Version 2.
Prerequisites
Interfaces must support Subnetwork Access Protocol (SNAP) headers.
Guidelines and Limitations
• Cisco Discovery Protocol functions only on Cisco devices.
• Cisco Discovery Protocol is not supported on Frame Relay multipoint subinterfaces.
Default Settings
Configuring CDP
This section includes the following topics:
• Configuring the CDP Characteristics, page 10-2
• Disabling and Enabling CDP, page 10-3
• Disabling and Enabling CDP on an Interface, page 10-4
Configuring the CDP Characteristics
You can configure the frequency of CDP updates, the amount of time to hold the information before
discarding it, and whether or not to send Version-2 advertisements.
CDP packets are sent with a time to live, or hold time, value. The receiving device will discard the CDP
information in the CDP packet after the hold time has elapsed.
You can set the hold time lower than the default setting of 180 seconds if you want the receiving devices
to update their CDP information more rapidly. The CDP hold time must be set to a higher number of
seconds than the time between CDP transmissions, which is set using the cdp timer command.
Feature Default Setting
CDP global state Enabled.
CDP interface state Enabled only on NNIs; disabled on ENIs.
Note CDP is not supported on UNIs.
CDP timer (packet update frequency) 60 seconds.
CDP holdtime (before discarding) 180 seconds.
CDP Version-2 advertisements Enabled.