1.3 Cisco Discovery Protocol

Vivinet Diagnostics uses Cisco Discovery Protocol (CDP) queries to discover Cisco Layer 2 devices that might be relevant to the Diagnosis. Until devices are discovered, Vivinet Diagnostics cannot send them SNMP queries to find out where network issues are occurring.

CDP is enabled by default on Cisco routers, switches, and CallManager Media Convergence Servers. If you disabled it on any piece of Cisco equipment, re-enable it.

NOTE:You may have disabled CDP as a workaround for Cisco vulnerabilities CSCdu09909 and CSCdv57576. If so, and you enabled LLDP (Link Layer Discovery Protocol) instead, you do not need to enable CDP. For more information, see www.cisco.com/application/pdf/paws/13621/cdp_issue.pdf.

To enable CDP:

  1. Issue the following command to find a router’s global configuration settings, including whether CDP is enabled:

    hostname# show cdp neighbors
    

    where “hostname#” is the DNS hostname of the router.

  2. Then issue the following commands:

    hostname# configure terminal
    hostname(config)# cdp run
    hostname(config)# end
    hostname# show cdp