This object indicates the alternate network layer address
(other than the one indicated by cdpCachePrimaryMgmtAddr) at
which the device will accept SNMP messages as reported in the
most recently received CDP message. If the corresponding
instance of cdpCacheSecondaryMgmtAddrType has the value 'ip(1)',
then this object would be an IP-address. If the most recently
received CDP message did not contain such an alternate network
layer address, then this object is not instanstiated.