coCdpCachePortId 1.3.6.1.4.1.8744.5.9.1.1.1.1.9

Indicates the Port-ID string as reported in the most recent CDP message. This will typically be the value of the ifName object (e.g., 'Ethernet0'). A zero-length string indicates no Port-ID field (TLV) was reported in the most recent CDP message.